Git Rev News

Git Rev News Edition 133 (March 31st, 2026)

chriscool — Tue, 31 Mar 2026 11:06:51 +0000

Git Rev News: Edition 133 (March 31st, 2026)

Welcome to the 133rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of February and March 2026.

Discussions

Support

git-am applies commit message diffs

On February 6, 2026, Matthias Beyer forwarded to the Git mailing list a surprising warning that had just circulated on Mastodon:

PSA: Did you know that it’s unsafe to put code diffs into your commit messages?

Such diffs will be applied by patch(1) (also git-am(1)) as part of the code change!

This is how a sleep(1) made it into i3 4.25-2 in Debian unstable.

The incident had originated in the i3 window manager project, where a commit message contained an unindented diff for illustration purposes. When Debian packagers later applied the patch using patch, the diff in the commit message was applied as actual code, sneaking a spurious sleep call into the Debian unstable package. Matthias asked the list whether this was a known issue and whether it could be an attack vector.

To understand why this happens, it helps to know how git am parses its input. When processing a patch email, it must split the stream into two parts: the commit message and the actual patch to apply. It does this by treating the first occurrence of any of the following lines as the boundary between the two:
- a line consisting of only three dashes (---),
- a line beginning with diff -, or
- a line beginning with Index: .
Everything before that boundary becomes the commit message; everything after is fed to the patch application machinery. Crucially, git am scans from the top of the email, so the very first such line it encounters terminates the commit message regardless of whether that line was meant to be part of the message text.

This design dates back to the tool’s origins. As Jeff King (also known as “Peff”) quickly explained in reply to Matthias, git am was originally designed to handle patches sent by all kinds of people, not just Git users. A contributor might have generated a diff with plain GNU diff and typed the rest of the email by hand, without any --- separator. The tool was therefore intentionally permissive: it would find a diff - line anywhere in the email and treat it as the start of the patch. Peff demonstrated this with a live example. He fed git am a hand-typed email containing a GNU diff, and it produced the expected commit.

This historical context also explained why git am is notoriously hard to fix: “I don’t think there is a way to unambiguously parse the single-stream output that format-patch produces,” Peff wrote, noting that he could find at least three earlier discussions of the same problem (in 2015, 2022, and 2024). The stream is simply ambiguous by design. Even the --- marker itself cannot be used to robustly split things, since --- on a line by itself is a valid diff hunk line indicating that the string -- was removed from a file.

Matthias proposed parsing from the end of the email rather than from the top. Peff replied that this would still be ambiguous for the same reasons, and would introduce new corner cases.

Jacob Keller noted early on that the issue was certainly surprising but that he was unsure it constituted a security attack vector, since someone should be reading the commit message before applying. But Matthias pushed back: the whole point was that nobody realized the behavior was there. He called it “sheer luck” that it was only a sleep and not something more malicious crafted as a diff in the commit message.

Florian Weimer wondered whether the git format-patch output was really ambiguous, given that the patch section is normally preceded by a diffstat block. Peff replied that the diffstat is optional and is not even parsed by the receiving side at all.

Jakob Haufe added an important nuance: even if git am was fixed to require indented diffs, it would only partially mitigate the problem, because patch (which many distributions use to apply upstream fixes to packages) is even more permissive. It will strip a consistent level of indentation from diffs before applying them. He quoted the patch(1) manual page: “If the entire diff is indented by a consistent amount, […] this is taken into account.” The i3 incident had in fact been triggered by patch, not git am.

Kristoffer Haugsbakk synthesized this into a clear summary of the situation and immediately proposed documenting it.

Matthias also highlighted the broader applicability beyond email workflows: Linux distributions like NixOS routinely fetch patches directly from upstream Git repositories and apply them to packages using patch. He noted that even after 15 years of using Git and being comfortable with email patch workflows, he himself had not known about this behavior.

Several directions were then explored to look for solutions.

Peff observed the irony that git format-patch does have an --attach option which puts the message and the patch in separate MIME parts — making them unambiguous in principle. However, git mailinfo (which powers git am under the hood) decodes both parts into a single stream and still treats a diff line in the message part as the start of a patch. Fixing this would require careful surgery to avoid breaking the existing forgiving handling of patches received as a single attachment.

Patrick Steinhardt suggested that even if parsing cannot be made unambiguous, git am could at least detect the ambiguity and bail by default with an --accept-ambiguous-patch override. Jacob Keller proposed going further: a new “unambiguous mode” where git format-patch would produce output that new versions of git am could distinguish unambiguously, while old versions would still handle the common case the same way as before.

Jacob had also sketched a concrete scheme: add a new unambiguous marker after the --- separator, so that old versions of git am would still cut at the --- and ignore everything up to the diff, while new versions would wait for the new marker and correctly ignore any diff appearing before it. Since the new marker would come after ---, it would not be inserted into the commit message when applied.

Peff replied that this was trickier than it sounded: the new marker would have to be something that could never appear legitimately in a commit message, and both sides would need to complain if they saw multiple markers. He explored further options: reversible quoting of --- and diff lines in the commit message (analogous to the >From quoting used in mbox files), applied only when the message would otherwise be ambiguous. This way, if an older git am received the mail, the worst case would be visible quoting in the commit message — ugly but readable. Junio Hamano, the Git maintainer, added another thought: refusing to accept unsigned patches at all.

Peff also proposed a simpler receiver-side improvement: a git am --strict mode that would always require a --- separator before the diff, on the assumption that well-formatted patches from Git always have one. This would not help with diffs that legitimately appear before the ---, but would eliminate the most common accidental cases.

None of these ideas led to an immediate implementation, as they all involve backward compatibility tradeoffs that would need careful thought.

On February 8, Kristoffer sent a documentation patch titled “doc: add caveat about round-tripping format-patch” which introduced a new Documentation/format-patch-caveats.adoc file explaining the behavior. The caveat was designed to be included in the documentation for git-am(1), git-format-patch(1), and git-send-email(1).

Junio reviewed version 1 and offered a correction to the wording: rather than saying that an unindented diff in the commit message “will not only cut the message short but cause that very diff to be applied, along with the patch in the patch section,” Junio noted that the outcome is not so deterministic. The diff in the commit message might get applied, or the patch machinery might trip on something and fail outright. He also flagged that the space after the --- in the cover letter was inconsistent with the project’s conventions.

Phillip Wood reviewed the patch and found the mention of git-send-email(1) a bit distracting, since that command merely runs git-format-patch(1) and does not do any formatting itself. He also suggested wording improvements: replacing “One might want to use […] patch(1)” with “Given these limitations, one might be tempted to […]”.

Kristoffer incorporated all of this in version 2, which dropped the git-send-email(1) mention from the introductory paragraph (while keeping the CAVEATS section in its documentation, for users who encounter it there), removed example code blocks in favor of clearer prose, and used the list of message-terminating patterns already present in git-am(1)’s documentation. Junio reviewed it and queued it with the comment “Nicely written.”

A third version, version 3, was submitted and received Junio’s approval to go to next.

Meanwhile, Phillip had observed that since the parsing cannot be fixed, “perhaps we should update our sample commit-msg hook to reject messages that will cause problems.” On February 7, he sent a 3-patch series titled “commit-msg.sample: reject messages that would confuse git am”. The series:
1. Added a .gitattributes rule for sample hooks (which are shell scripts but have .sample extensions).
2. Extended the sample commit-msg hook to scan the body of the commit message for unindented diff - and Index: lines and reject the commit with a helpful error message.
3. Added a further check to detect --- separator lines in the message body, which would cause git am to silently truncate the commit message.
Peff reacted with measured skepticism to patch 3 in version 1: he and Junio both pointed out that they themselves sometimes use --- intentionally in commit messages to add notes that will appear in the formatted patch email but not end up in the final commit message when applied. Junio explained the trick: “when I know what I want to write below the three-dash lines, I would commit with --- and additional notes below it, so that I do not forget during format-patch. When the commit is turned into a patch email […] am cuts at the first one, and apply knows that the garbage lines at front, including three-dash lines, do not matter until it sees ^diff, this works out perfectly well.”

Peff confirmed he used the same trick. Phillip, acknowledging that at least three developers relied on this behavior, decided to drop patch 3 entirely, reducing the series from three patches to two in version 2. He also refined the diff detection in the body: the v2 correctly skips the first paragraph of the message (which becomes the email Subject header and so does not go through the patch boundary detection), skips lines below a scissors line, and handles the core.commentChar and core.commentString configuration options for determining which lines are comments. Junio reviewed version 2 with detailed questions about the scissors-line logic.

Kristoffer verified that version 2 worked with git commit --cleanup=scissors --verbose and was satisfied.

The discussion did not lead to a fundamental fix to the ambiguous parsing in git am, which remains an open problem with no obvious backward-compatible solution. But it produced two concrete improvements that were accepted and are now in master: a CAVEATS section in the documentation for git-am(1), git-format-patch(1), and git-send-email(1) spelling out exactly how commit messages can inadvertently interfere with patch application, and an enhanced sample commit-msg hook that rejects messages containing unindented diffs.

The thread also served as a useful reminder that this problem is not limited to email workflows: any project that generates patches from Git commits using git format-patch and applies them with patch or git am is exposed to it. The practical advice for authors is simple: if you include diffs in commit messages for illustrative purposes, make sure to indent them consistently, and be aware that even that does not protect you from patch.

Developer Spotlight: Olamide Caleb Bello

Editor’s note: This edition features a retrospective interview with a contributor who contributed to Git through a mentoring program. We hope the reflections shared by the Outreachy contributor will provide an insightful perspective that benefits the community. As always, we welcome your thoughts and feedback!

Who are you and what do you do?

I’m Olamide Caleb Bello, a software engineer based in Nigeria. I studied Economics, but I’ve always been curious about technology and how systems work behind the scenes. That curiosity led me to start teaching myself web development, and over time I found myself drawn more towards backend and systems-oriented work.

I became especially interested in understanding how complex tools are built and maintained, which led me to open source. I contributed to Git as part of the Outreachy program, where I got to work on improving parts of Git’s internal workflows.

These days, I enjoy working on tools that make development smoother for others, and I’m particularly interested in open source and distributed systems.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your Outreachy project?

I initially saw Git as just a tool I needed to get my work done. For a long time, my workflow was basically just git add, git commit, git push, and git pull, without thinking much about what was happening underneath. That started to change when I ran into some particularly messy merge conflicts that forced me to slow down and really question how Git was managing history and combining changes.

Around the same time, I was becoming more interested in systems in general, thinking about tools like the kernel, systemd, and Git itself, and how they work under the hood. That experience pushed me to look deeper into Git’s internals, and I quickly realized how much depth there was beneath the surface.

When I came across the Outreachy project, choosing Git felt natural, I wanted to challenge myself and contribute to a tool I had used for years but didn’t fully understand, while learning from experienced maintainers.
How do you feel your contribution has impacted the Git community or the broader open source ecosystem?

My work focused on reducing Git’s reliance on global state by refactoring repository-specific variables into a more localized structure. Each repository instance now manages its own configuration independently, improving modularity and reducing the risk of cross-repository issues.

Through this work, I came to appreciate how changes at this level contribute to Git’s long-term direction, particularly efforts to make it more reusable as a library. Even though these changes aren’t directly visible to users, they make the system safer and easier to extend.

Being part of that process gave me a deeper respect for the level of thought and the care that goes into maintaining Git.
Is there any aspect of Git that you now see differently after having contributed to it?

Before contributing, I thought Git was just a bunch of commands I typed every day. Working on it showed me a whole hidden world, how configurations are saved and read, how each repository handles its own settings, and what the index is really doing behind the scenes. Some of it was so intricate I almost felt like Git was trolling me!

Seeing all this up close turned what felt like a simple tool into a carefully designed system, and it gave me a much deeper appreciation for the thought and care behind every command.
How do you balance your contributions with other responsibilities like work or school?

At the moment, I’m not tied to a full-time job or school, but I spend a lot of time learning new tech and doing freelance work. I usually dedicate small, focused sessions to Git contributions, sometimes just an hour here or there, and it’s surprising how much progress you can make that way. This rhythm lets me keep learning, experimenting, and contributing without feeling overwhelmed.
Can you share how Outreachy helped enhance your technical and non-technical skills (like communication, project management, etc.)?

Outreachy was a huge growth opportunity for me, both technically and personally. On the technical side, I deepened my understanding of Git internals, learned to work effectively in a large C codebase, and tackled complex refactoring of core systems. On the non-technical side, I honed my communication skills by engaging actively on the Git mailing list, responding to feedback, and documenting my work clearly for others. The experience also helped me improve project discipline, learning how to plan and iterate on tasks in a structured way.
What was your biggest takeaway or learning from Outreachy that you now apply regularly in your work?

My biggest takeaway from Outreachy was learning how even small, careful changes can have a big impact in a large system like Git. During Outreachy, for even the tiniest change, I had to run over 32,000 test cases just to be sure it wouldn’t break anything! I approach my work by breaking tasks into smaller steps, testing thoroughly, and thinking through the consequences before making changes. This mindset has become a regular part of how I work, whether I’m contributing to open source or building my own projects.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

The toughest part of contributing to Git was navigating its huge and complex C codebase. I had to wrap my head around global variables, repository-specific state, and how configs were stored and read. At first, it felt overwhelming, and I constantly worried that even a small change might break something.

I overcame this by tackling one piece at a time, reading the code carefully, testing thoroughly, and admittedly, disturbing my mentors quite a bit! 😂 I’m especially grateful to Christian Couder and Usman Akinyemi, who guided me patiently. Christian taught me how to ask questions properly, showed me how to debug effectively, and always encouraged me to think through problems step by step. Usman was equally supportive, often checking in and joining coding sessions with me. Both helped me understand Git’s internal architecture and gave me the confidence to contribute safely and effectively.
Have you thought about mentoring new GSoC / Outreachy students?

Yes, I have thought about mentoring future GSoC or Outreachy students. Since I’m still relatively new to open source myself, I want to focus on contributing and learning for now. However, I do hope to co-mentor in the next Outreachy program, sharing what I’ve learned and helping others navigate the experience.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

If I had a team of expert developers working full time on Git for a year, I would focus on further improving its modularity and internal architecture. My goal would be to make Git easier to embed and reuse as a library, reducing reliance on global state and improving the safety of multi-repository operations.

This would not only make Git more maintainable for contributors but also open up new possibilities for other projects to integrate Git functionality more easily.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

If I could remove anything from Git without worrying about backwards compatibility, I’d simplify some of the legacy parts of its internal state. These older structures can be confusing and tricky to work with, and removing them would make Git’s internals cleaner and easier to reason about.
What upcoming features or changes in Git are you particularly excited about?

I’m particularly excited about Git’s ongoing libification efforts, which make it easier for other projects to embed and reuse Git functionality. Changes that reduce global state and improve repository isolation also excite me, because they make multi-repository operations safer and Git’s internals easier to work with. I’m curious to see how these improvements will open up new possibilities for both contributors and external tools that rely on Git.
What is your favorite Git-related tool/library, outside of Git itself?

I’d say my favorite Git-related tool is gitingest. It’s really handy for exploring repositories programmatically and testing workflows. I’ve found it especially useful while learning Git internals.
What is your toolbox for interacting with the mailing list and for development of Git?

I mainly use git send-email to submit patches, read threads on lore.kernel.org/git, and reply via Gmail. This setup helps me follow discussions and iterate on my contributions smoothly.
How do you envision your own involvement with Git or other open source projects in the future?

I’m here to stay in open source. I want to keep contributing to Git and other projects, learning as I go, taking on bigger challenges, and helping new contributors find their footing. Open source has become a big part of how I grow as a developer, and I hope to keep giving back for years to come.
What is your advice for people who want to start Git development? Where and how should they start?

My advice for anyone starting Git development is to begin small and be curious. A great resource I found helpful is the MyFirstContribution document. Start by reading the guides, experimenting locally, and submitting small patches. Interacting with the mailing list, asking questions, and iterating on feedback will help you learn and grow as a contributor.
Would you recommend other students or contributors to participate in the GSoC, Outreachy or other mentoring programs, working on Git? Why? Do you have advice for them?

Absolutely, I would recommend programs like GSoC or Outreachy for anyone interested in Git or open source. These programs provide structured mentorship, exposure to real-world projects, and the chance to learn directly from experienced developers. My advice is to start small, be curious, ask questions, and don’t be afraid to iterate on feedback. Every contribution, no matter how minor it may seem, is a valuable learning experience.

Other News

Various

The forge is our new home. by Tomáš Hrčka on Fedora Community Blog.
After a full year of preparation, the Community Linux Engineering (CLE) team announced that Fedora Forge, powered by Forgejo, is ready for use. If you own a project at pagure.io, you must migrate out of it before June 2026; the How to Migrate Repository from Pagure guide is there to help with this task. Note that Fedora Forge is narrower in scope than pagure.io; it is provisioned to host the code, documentation, and tooling that directly build, manage, and govern the Fedora Project. Personal projects and general upstream development do not belong on Fedora Forge.
GNOME GitLab Redirecting Some Git Traffic To GitHub For Reducing Costs by Michael Larabel in GNOME on Phoronix.
Radicle: Disclosure of Replay Attack Vulnerability in Signed References
- Radicle is a peer-to-peer, local-first code collaboration stack built on Git. It was first mentioned in Git Rev News Edition #49 and most recently in edition #131.
  Compare with Tangled (built on top of AT Protocol), Grasp and git str (built on top of Nostr).
b4’s Review TUI With AI Integration Nearing Pre-Alpha Release by Michael Larabel in the Linux Kernel section on Phoronix.

Light reading

The Comforting Lie Of SHA Pinning by Aiden Vaines on Vaines.org. The recommendation to pin your dependencies in GitHub Actions translates to using commit SHAs, not tags - which can be moved (though GitHub already has optional ‘Make tags immutable’ feature). However, GitHub Actions does not meaningfully validate that the commit SHA you reference belongs to the repository you think it does: it can belong to a hostile fork.
Git Remote Helpers: how to create git-remote-swh that would let you git clone from a SWHID, pulling source code directly from Software Heritage’s archive by content hash rather than by URL. Written by Andrew Nesbitt on his blog. Also lists built-in remote helpers, and lists third-party helpers: for cloud and object storage, for content-addressed storage, for encryption, for VCS bridges, for P2P and decentralised (though this list was missing git-remote-rad for Radicle), for a different transport layer, for blockchain, for other storage backends.
Git Bayesect by Shantanu Jain (@hauntsaninja) on his blog. It describes the idea behind git bayesect, which is a generalisation of git bisect that uses Bayesian inference to solve the problem of flaky, non-deterministic tests.
Git Tricks with Tri and Difft by Nabeel Valley on their blog.
- Tri is a TUI interactive directory tree browser, and difft, or Difftastic is a structural diff tool that understands syntax. Difftastic was first mentioned in Git Rev News Edition #86, and most recently in Edition #131.
Awesome Git Diffs with Delta, fzf and a Little Shell Scripting by Nick Janetakis on his blog.
- delta (from ‘git-delta’ package) is a syntax-highlighting pager for git, diff, grep, and blame output, first mentioned in Git Rev News Edition #9, and most recently in Edition #131.
  fzf is a command-line fuzzy finder, first mentioned directly in Git Rev News Edition #74 (in passing first in Edition #64), and most recently in Edition #130.
Build Git helpers from scratch with Bash and fzf and Improve your Git CLI experience with Git aliases, delta, and custom functions by Olivia Coumans on her blog.
Taming a 486MB Git Repo (with source code taking 6MB) by Harisankar P S on his HsPS.in blog.
CodeCity: Turning a Codebase into a Skyline, about a polyglot (multi-language) CodeCity visualizer built in Rust, rendering codebases as interactive 3D cities. In this tool, modules are shown as buildings, grouped together in districts corresponding to top-level packages (squarified treemap), with footprint corresponding to size in lines of code, height corresponding to complexity, and color corresponding to “health”. Follows from the Legibility: A Scaling Bottleneck of the Agentic Era essay.
“Use git worktrees,” they said. “It’ll be fun!” they said. by Dave Schumaker on his blog. This post describes a problem with often used solutions like symlinked node_modules or .venv directories, Yarn’s hardlinks-global mode, APFS Copy-on-Write (cp -c) - which is also supported by other filesystems. Proposes keeping a fixed pool of 6 worktree slots, and recycling them as needed.
Direnv is All You Need to Parallelize Agentic Programming with Git Worktrees by Walden Cui on The Search Blog.
See also, for example:
- I Built workz: The Zoxide for Git Worktrees That Finally Fixes .env + node_modules Hell in 2026, mentioned in Git Rev News Edition #132.
- Git Worktrees with Claude Code, Laravel, and Herd, mentioned in Git Rev News Edition #132.
- Why You Should Be Using Git Worktrees, mentioned in Git Rev News Edition #129.
- tree-me: Because git worktrees shouldn’t be a chore, mentioned in Git Rev News Edition #129.
- Managing Multiple Claude Code Sessions Without Worktrees, mentioned in Git Rev News Edition #125.
- How to use git worktree effectively with Python projects, mentioned in Git Rev News Edition #125.
Using Git with coding agents is a chapter from the guide Agentic Engineering Patterns, available on Simon Willison’s Weblog.
How I organize git repos locally by Mansoor Majeed on their Esc.sh blog.
SSH certificates and git signing on Matthew Garrett’s Blog.
- Signing Git Commits with SSH Keys was first mentioned in Git Rev News Edition #83.
- See also Git signatures with SSH certificates by Matthew Garret on his old mjg59’s journal blog, mentioned in Git Rev News Edition #91.
Choosing the best git branching strategy for continuous delivery in your team by Geshan Manandhar on his blog: compares Git-Flow, GitHub Flow, and Trunk-based development, recommending GitHub Flow.
- See also Patterns for Managing Source Code Branches by Martin Fowler (author of the Refactoring: Improving the Design of Existing Code book), which was first mentioned in Git Rev News Edition #63.
Git: Remove Dead Branches by Nathan Long on his blog. The script described in detail should probably use git for-each-ref rather than parse the user-facing git branch command, though.
Selectively ignore lines in git diff by using git diff --ignore-matching-lines=<regexp> (or -I in short). Article by Lorna Jane Mitchell on her LornaJane blog.
Git: ignoring temporary changes by Olivier Mehani on Narf blog. He proposes using git update-index --assume-unchanged <PATH>, which is not safe; a safer solution is to use --skip-worktree instead (won’t lose changes, may prevent safe operation).
- Compare Use skip-worktree to ignore modified files by Brandon Pugh, mentioned in Git Rev News Edition #129.
SQLite on Git, Prologue: Why do we need random access in git and SQLite on Git, Part I: The .git folder - Falling down the Rabbithole are the first two parts of an upcoming series of blogposts, where the author shares research enabling one to have a version controlled filesystem that allows running a versioned SQLite database on top of Git’s internal storage. Written by Martin R. Lysk on his blog.
- Contrast Git in Postgres by Andrew Nesbitt mentioned in Git Rev News Edition #132.
GotHub all the things by 𝚐𝚘𝚗𝚣𝚊𝚕𝚘 on x61.sh blog.
- The Game of Trees Hub (GotHub) is a transparently funded Git repository hosting service, with infrastructure on OpenBSD and the Game of Trees (GoT) VCS, mentioned in Git Rev News Edition #131 and #132.
An easy way to mirror git repositories with the help of author’s little shell script “ferne”.
Rebasing in Magit by kqr (Chris) on Entropic Thoughts.
- Magit is a popular Emacs editor interface to Git, first mentioned in Git Rev News Edition #6, and most recently in Edition #130 and #132.
Reviewing large changes with Jujutsu by Ben Gesoff on his blog.
- Jujutsu (jj) is a Git-compatible version control system, written in Rust, which was first mentioned in Git Rev News Edition #85.
Magit and Majutsu: discoverable version-control by Daroc Alden on LWN.net.
- Majutsu provides a Magit-style interface for Jujutsu (jj) in GNU Emacs. First mentioned in Git Rev News Edition #132.
Editing changes in patch format with Jujutsu VCS by Katalin Rebhan (@dblsaiko) on her blog.
Manyana: A Coherent Vision for the Future of Version Control and More on Version Control: This may have some legs by Bram Cohen on Bram’s Thoughts, about his approach of using CRDTs (Conflict-free Replicated Data Types) for version control.
The ideas behind Manyana, with a prototype written in Python, looks a bit similar to Codeville, a distributed version control system created around 2005 by Ross and Bram Cohen, with a unique merging algorithm, no longer existing.
Development tools: Sashiko, b4 review, and API specification by Jonathan Corbet on LWN.net (free link).
- Konstantin Ryabitsev’s b4 tool was first mentioned in Git Rev News Edition #61, and most recently in Edition #127. It is also listed on the Hacking Git page.
Mercurial at Google: Also known as Fig, slides by Martin von Zweigbergk, presented at 2023-04-06.
Automate Your Code with GitHub Actions (Part 1 and Part 2) by Bas Steins on Tower’s Blog.

Scientific papers

Benedikt Schesch, Ryan Featherman, Kenneth J Yang, Ben Roberts, and Michael D. Ernst: “Evaluation of Version Control Merge Tools.“ at 39th IEEE/ACM International Conference on Automated Software Engineering (ASE ‘24). Association for Computing Machinery, New York, NY, USA, 831–83. https://doi.org/10.1145/3691620.3695075
- Authors evaluated (using Java projects from GitHub’s Greatest Hits and RepoReapers / Reaper datasets) the following CLI tools: different variants of the git merge algorithm, git-hires-merge, IntelliMerge (Java only), Spork (Java only), and their own Plume-lib merging.
- They considered, but did not evaluate JDime (Java only) because of its limitations, as well as AutoMerge (also known as AutoMerge-PTM), DeepMerge, and MergeBERT because those tools are not publicly available. They could not evaluate tools based on GUI interaction, like RefMerge (IntelliJ IDEA plugin) or FSTMerge (part of FeatureHouse, depends on KDiff3).
- Mergiraf did not exist at the time this paper was written. Mergiraf was mentioned in Git Rev News Edition #117, #119 (in passing), and #129.
- SemanticMerge, a proprietary tool with a 15 or 30 day trial, might have been defunct then (since 2013); nowadays its homepage page is taken by SEO spam. It was mentioned in Git Rev News Edition #38.
Joao Pedro Duarte, Paulo Borba, and Guilherme Cavalcanti: “LastMerge: A language-agnostic structured tool for code integration” preprint on arXiv:2507.19687 (25 July 2025). It compares four structured merge tools: two Java specific tools, JDime and Spork, and their generic counterparts, Mergiraf and their own LastMerge tool (currently not available), respectively.
- They also mention s3m (Semistructured 3-Way Merge) for Java.
Qingyu Zhang, Junzhe Li, Jiayi Lin, Jie Ding, Lanteng Lin, and Chenxiong Qian: “WizardMerge—Save Us from Merging without Any Clues.” ACM Transactions on Software Engineering and Methodology, Volume 35, Issue 1; Article No.: 22 (11 December 2025), 28 pages. https://doi.org/10.1145/3731751
- An open-source code-merging auxiliary prototype named WizardMerge, together with evaluation datasets, is available on GitHub. Written in C++.

Git tools and sites

A Partial Extract of revctrl.org, a Revision Control wiki, which has fallen victim to spam, and is now taken over. Scraped, archived, and edited by Tony Garnock-Jones; spam cleanup and improvements to formatting by Michael Haggerty. Unfortunately, all the edit history of the wiki was lost, and individual pages do not have clear authorship.
Version Control with Git for Data Science, a part of Research Guides for the data science community at New York University.
References Software Carpentry “Version Control with Git”, mentioned in Git Rev News Edition #86.
git bayesect: Bayesian git bisection. You can use this tool to detect changes in likelihoods of events, for instance, to isolate a commit where a slightly flaky test became very flaky. You don’t need to know the likelihoods (although you can provide priors), just that something has changed at some point in some direction. If your code has started gaslighting you, give it a try! Written in Python, under MIT license.
GitStats is a statistics generator for Git repositories. Currently it produces only HTML output with tables and graphs, providing total files, lines, commits, authors, commits by hour of day, day of week, etc. Fork of http://gitstats.sourceforge.net/. Written in Python, under GPLv2 or older license.
Original version demo available at http://gitstats.sourceforge.net/examples/gitstats/.
GitTop is terminal UI tool for visualizing Git repository statistics, inspired by htop/btop. Written in Go, under BSD-3-Clause license.
- See also My First Fully Agentic Coding Project: GitTop by Mahmud Ridwan on hjr265.me.
diffsoup is a Gerrit-style TUI patchset diff viewer for pull requests, using Jujutsu. Written in Rust, under MIT license.
fzf-git.sh: bash, zsh, and fish key bindings for Git objects, powered by fzf. Each binding will allow you to browse through Git objects of a certain type, and select from TUI the objects you want to paste to your command-line. Under MIT license.
Git X-Modules is a tool to manage modular Git projects. Alternative to the built-in git submodule (see also Git Tools - Submodules chapter in “Pro Git” 2nd Ed.), git subtree (which uses the built-in subtree merge strategy), git stree, and git subrepo.
GitBucket is an Open Source Git platform on JVM (a software forge), with easy installation, high extensibility & GitHub API compatibility. Written in Scala, under Apache License Version 2.0.
CodebaseHQ by Krystal is a software forge that offers Git, Mercurial and Subversion hosting, with project management tools. No free tier, 15 day free trial.
git-memento is a Git extension that records the AI coding session used to produce a commit. It attaches AI conversation transcripts as git notes, creating an audit trail for AI-assisted development. Written in F# and TypeScript, under MIT license.
ChunkHound is a local-first codebase intelligence, which researches your codebase, extracting architecture, patterns, and institutional knowledge, to give your AI assistant the context it needs - deep understanding of your code, files, and architectural decisions. Integrates via MCP (Model Context Protocol). Written in Python, under MIT license.
Sashiko is an agentic Linux kernel code review system, using a LLM (Large Language Model). It monitors public mailing lists to thoroughly evaluate proposed Linux kernel changes. The system acts like a team of specialized reviewers covering domains from high-level architecture verification and security audits to low-level resource management and concurrency analysis. It is an open-source project that belongs to the Linux Foundation, licensed under the Apache License, Version 2.0.

Releases

Git for Windows v2.52.0(2), v2.51.2(2), v2.53.0(2)
Bitbucket Data Center 10.2
Gerrit Code Review 3.11.10, 3.11.9, 3.12.5, 3.12.6, 3.13.4, 3.13.5, 3.14.0-rc0
GitHub Enterprise 3.20.0, 3.19.4, 3.18.7, 3.17.13, 3.16.16, 3.15.20, 3.14.25
GitLab 18.10.1, 18.9.3, 18.8.7, 18.10, 18.9.2, 18.8.6, 18.7.6
GitKraken 11.10.0
GitHub Desktop 3.5.6
Garden 2.6.0
Git Cola 4.18.2, 4.18.1, 4.18.0
GitButler 0.19.6, 0.19.5
Tower for Mac 16.0 (Beta)
Tower for Windows 11.2

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Olamide Caleb Bello, Bruno Brito, Štěpán Němec and Kristoffer Haugsbakk.

Git Rev News Edition 132 (February 28th, 2026)

chriscool — Sat, 28 Feb 2026 11:06:51 +0000

Git Rev News: Edition 132 (February 28th, 2026)

Welcome to the 132nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of January and February 2026.

Discussions

Support

Slow git pack-refs –all

Martin Fick started the discussion by reporting a significant performance issue where git pack-refs --all was taking over five minutes to complete on a large repository (~3M refs) hosted on an NFS filesystem. This delay was particularly problematic for Gerrit servers because Git holds the packed-refs.lock for nearly the entire duration, blocking other reference updates. Martin noted that JGit was able to perform the same operation in under 20 seconds on the same repository, suggesting the bottleneck was specific to the Git implementation.

The packed-refs file is used by Git to store a large number of references in a single sorted file to avoid the overhead of many small “loose” reference files. However, updating this file requires rewriting it entirely, and Git typically verifies that objects exist and “peels” tags (finding the underlying object a tag points to) during this process.

brian m. carlson replied to Martin, suggesting that the slowdown might be occurring in should_pack_ref() because Git needs to verify that the object at the end of a reference actually exists. brian also pointed out that NFS was likely a major factor, as the network latency involved in opening many pack files and checking loose objects can be substantial. He suggested setting receive.unpackLimit to 1 to reduce the number of loose objects created in the first place.

Jeff King (alias Peff) explained that the packed-refs file stores “tag-peeling” information, which requires Git to open each object for newly written refs via peel_object() to read its header and determine its type. Peff noted that this logic resides in write_with_updates() within packed-backend.c.

Martin conducted further testing using strace and drop_caches to eliminate filesystem caching interference. He discovered that while the actual write() calls were fast, there were long gaps—up to four minutes in total—where the program was not making any system calls. Martin hypothesized that this “hidden” time was spent by the kernel handling page faults for mmap()ed memory over NFS.

Patrick Steinhardt concurred that NFS was frequently a source of such performance issues, mentioning that GitLab had eventually sunsetted the use of NFS for this reason. Patrick suggested using perf(1) to generate a flame graph to see exactly where the CPU was spending time.

Martin provided a summary of a flame graph, which showed about one-third of the time spent in _memcmp_sse4_1 and another third in unpack_object_header_buffer(), both accompanied by high page fault rates. He also noticed significant time spent in a function he identified as packed_refs_store_create().

Peff corrected the function name to packed_ref_store_create() and noted that Git might be performing an extra linear pass through the packed-refs file if it lacks certain header tags. He discovered that JGit-generated files were missing the sorted and fully-peeled traits in the header. Without the sorted tag, Git reads the entire file linearly to verify its order before it can perform binary searches. Peff suggested that JGit should be updated to write these markers.

In a final breakthrough, Martin tested adding these tags manually. He found that while the sorted tag did not provide a major boost, adding the fully-peeled tag was the “trigger” that dropped the execution time from over five minutes to under four seconds. The absence of the fully-peeled tag was forcing Git to re-peel every reference by looking up the objects in the pack files over the slow NFS connection.

Following that discovery, a fix was proposed for JGit in Change 1230152. Adithya Chakilam submitted the patch, titled “pack-refs: Add sorted/fully-peeled flags,” to ensure JGit produces packed-refs files that Git can process efficiently.

This resolution not only fixes the immediate performance issue for Gerrit servers but also ensures that any environment using a mix of JGit and Git will benefit from reduced lock contention and faster reference updates.

Other News

Various

What’s new in Git 2.53.0? by Justin Tobler on GitLab Blog. The described changes include fixes for geometric repacking (adding support for promisor remotes), updates to git fast-import commit signature handling options, and more data being available in git repo structure output.
Git 2.53 Released with New Features and Performance Improvements by Marcus Nestor on 9to5Linux.
Git 2.53 Released With More Optimizations, One Step Closer To Making Rust Mandatory by Michael Larabel on Phoronix.
Gentoo Linux has kicked off its long transition away from Microsoft’s GitHub to Codeberg, an open-source Git-hosting service: see the PC Gamer article by Joshua Wolens, and the Gentoo on Codeberg article in Gentoo Linux News.
Vinyl Cache project (formerly Varnish Cache) has left GitHub for the self hosted Forgejo instance: https://code.vinyl-cache.org/vinyl-cache/
Game of Trees Hub’s web interface is live.
- The Game of Trees Hub is a transparently funded Git repository hosting service, with infrastructure on OpenBSD and the Game of Trees (GoT) VCS, mentioned in the previous edition.
Exploring Solutions to Tackle Low-Quality Contributions on GitHub by Camilla Moraes (@moraesc) on GitHub Community Discussions.
The Former CEO of GitHub [Thomas Dohmke] Just Agreed: Git Wasn’t Built for This [AI-based coding] by Jeff Cameron on OpZero blog, following his “interview” with Claude Opus 4.5. The idea is to version code, intent, constraints, and reasoning together, and to add a semantic reasoning layer through a “context graph”. Thomas Dohmke has launched such an open-source developer platform for collaboration between developers and AI agents, Entire.
- On one hand this assumes that AI generated code is a viable path to creating software, and there would be no technical problems like model collapse, or economical problems like cost of training and using LLMs.
- On the other hand there exist specialized solutions to help version data (like DVC or Pachyderm) or database schemas.

Light reading

Evolving Git for the next decade by Joe Brockmeier on LWN.net, reporting about Patrick Steinhardt’s (@pks-t) main track talk at FOSDEM 2026. The recording of this talk is available on the FOSDEM site.
Exploring the .git Directory – How Git Stores Your Code by Bruno Brito on Tower’s Blog.
The Ultimate Guide to Git Config: Fine-Tuning Your Git Experience by Bruno Brito on Tower’s Blog.
TIL that pathnames in git configs can be optional by Anh Tuan Le on his blog. It mentions the fact that as of Git 2.52 (Nov 2025), you can mark config file paths as optional using the :(optional) prefix; see the ‘pathname’ entry in the “Values” section of the git config manpage.
Git Reflog Explained: Recover Deleted Commits & Lost Work by Shakil Alam on DEV.to. Has a video version.
How to Save Multiple Drafts in Git: A Guide to Using Git Stash by Chidiadi Anyanwu on freeCodeCamp.
Git renames are not renames (and where it can cause problems) by Lorna Jane Mitchell on LornaJane Blog.
The Many Flavors of Ignore Files by Andrew Nesbitt on his blog. The post talks about Git’s actual semantics for “gitignore syntax”.
- The author wrote git-pkgs/gitignore, a Go library that fully matches how Git’s gitignore patterns work.
git recent: what branch did I work on?, about a simple Git alias, by Remy Sharp on his blog.
I Hate GitHub Actions with Passion by Przemysław Alexander Kamiński on his xlii.space blog.
- The main problem is with trying to debug GitHub Actions problems when the action fails; Act, a command line tool to run your GitHub Actions locally using the Docker Engine API, could help there. Act was first mentioned in Git Rev News Edition #113.
- There is also WRKFLW, a command-line tool for validating and executing GitHub Actions workflows locally, without requiring a full GitHub environment. WRKFLW was mentioned in Git Rev News Edition #126.
GitHub Actions: The Hidden Billing Trap, on how to avoid unexpected costs with a simple settings adjustment. Written by Steven Hicks on TheExceptionCatcher.
Git Worktrees with Claude Code, Laravel, and Herd by Jakub Gause on his blog (also published on DEV.to). Describes writing a shell script to help (a laravel-worktrees Claude skill).
I Built workz: The Zoxide for Git Worktrees That Finally Fixes .env + node_modules Hell in 2026 by Rohan Sharma on DEV.to. Describes his workz tool that creates a new worktree, automatically symlinks 22+ types of dependency dirs (like node_modules, target, .venv), copies env/config patterns, and can launch your AI coding agent directly in the new worktree.
Agent Identity for Git Commits by Justin Poehnelt on his blog, about how to set up AI agents to have their commits come from a bot account without modifying your local Git config.
Your Secrets Aren’t Safe: How the .git Directory Can Leak Data via AI Tools by Yohei Seki on DEV.to. The problem is that a malicious MCP server or Skill can access leaked secrets even if they were removed from the project (you should treat any committed secret as compromised, and invalidate it; using git filter-repo or BFG RepoCleaner to rewrite history might be a choice). They can also access authentication information if embedded in .git/config.
Git in Postgres by Andrew Nesbitt on his blog (following Package managers keep using git as a database, it never works out, mentioned in Git Rev News Edition #130 from December). In this post he describes how he created a Git backend using a relational database: gitgres (implementing the libgit2 git_odb_backend and git_refdb_backend interfaces against PostgreSQL through libpq). He acknowledges that right now gitgres is just a neat hack, as it currently does not implement delta compression; nevertheless it might be a good solution for small instances of software forges for small projects.
- Compare with git-remote-sqlite, a Git remote protocol helper that helps you store a Git repository in a SQLite database, mentioned in Git Rev News Edition #127.
The nightmare that is squash merge ft GitHub by Narendra Vardi on his blog, about how to fix merge conflicts caused by squash merge using interactive rebase.
How Poor Git Branching Practices Quietly Damage Software Quality by AK DevCraft on Substack (and also on DEV.to), about the Environment-Based Branching antipattern.
- The Patterns for Managing Source Code Branches by Martin Fowler, mentioned first in Git Rev News Edition #63, also talks about this antipattern.
Why [pure] GitOps Doesn’t Work at Scale (and What to Do Instead) by Justin Brooks (@jsbrooks) at ctrlplane (also on DEV.to). He writes why enterprise scale workflows need platform-level orchestration.
GitHub Actions Is Slowly Killing Your Engineering Team and No, Really, Bash Is Not Enough: Why Large-Scale CI Needs an Orchestrator by Ian Duncan on his blog.
My self-hosted Git workflow with GitGen by cybrkyd; it continues Showcasing my Git repositories on the web from the previous edition.
- GitGen is a lightweight static website generator for local Git repositories written in Python; similar tools are Gitmal and pgit, both written in Go.
The bare minimum for syncing Git repos by Alex Chan on her blog.
The Disconnected Git Workflow by Lionel Dricot (Ploum) (sidenote: there is also git-credential-oauth that can solve some of the problems with sending a small one-off patch to a GitHub project).
git.usebox.net and bots by Juan J. Martínez on his Personal Log, about his modification of gitweb to block AI crawlers (that do not respect robots.txt).
I Built a Tool That Writes Obituaries for Your Deleted Code and commit-prophet: I Built a Tool That Predicts Buggy Files Using Git History by Lakshmi Sravya Vedantham on DEV.to.
I Read 9,000 Lines of a Stranger’s Mergetool by Wes on DEV.to, about the ec (easy-conflict) tool. This is the first entry in the Review Bomb series, where Wes finds under-the-radar projects on GitHub, reads the code, contributes something, and writes it up.
Return to GitHub by Glyn Normington on the underlap blog; the move of ipc-channel-mux from Codeberg to GitHub was caused by the need for CI on macOS and Windows (without having to self-host CI runners).
Simplifying Git by Using GitButler: seeing Git state, branching without fear, understanding and using stacked changes, better interactive rebase, easier selective staging, recoverability. Written by PJ Hagerty on GitButler Blog. Git Butler was first mentioned in Git Rev News Edition #46.
GitButler CLI Is Really Good by @matdevdug on matduggan.com.
Introducing jjq, a local merge queue for jj by Paul Smith on his blog. Jujutsu (jj) is a Git-compatible version control system written in Rust, which was first mentioned in Git Rev News Edition #85.
15+ years later, Microsoft morged my diagram by Vincent Driessen, on how Microsoft’s Learn portal included an AI generated diagram with the rough shape of the one in the A successful Git branching model, but with some GenAI glitches (like the text “Bugfixes from rel, branch may be continvoucly morged back into develop”), and arrows missing or pointing in the wrong direction, or missing the node. The image has been replaced since then; you can see the original compared to the Microsoft one in the PC Gamer article about this issue.

Easy watching

Evolving Git for the next decade by Patrick Steinhardt [47:46], a main track talk at FOSDEM (Free and Open source Software Developers’ European Meeting), given on Saturday, 31 January 2026, Brussels. See also the summary of this talk by Joe Brockmeier on LWN.net (mentioned in the “Light reading” section).
An Efficient Git Workflow For High-Stakes Projects by Vladislav Shpilevoy [45:12], a main track talk at FOSDEM, on Saturday, 21 January 2026, Brussels. The example project this workflow was used in is tarantool.
Pull requests maintainers will love to review by Alya Abbott, a main track talk at FOSDEM, on Saturday, 21 January 2026, Brussels. Slides available as Google Slides.
Mercurial, 20 years and counting: how are we still alive and kicking? by Raphaël Gomès and Pierre-Yves David [50:02], a main track talk at FOSDEM, on Saturday, 21 January 2026, Brussels.
Lost Your Commits? Git Reflog Saves You by Shakil Alam on the Shakil Tech channel on YouTube [5:55].
Configure your Git by Denis Gruzdev aka @codingjerk on the codingjerk channel on YouTube [14:02]: a brief review on their personal git config / setup, showing some of the most used commands, settings, and aliases.

Git tools and sites

mise-en-place or mise, a CLI tool that is the front-end to your dev env (managing dev tools like node, python, cmake, terraform, etc; and managing tasks used to build and test projects), introduced monorepo tasks, allowing you to manage tasks across multiple projects in a single repository, with each project maintaining its own tools, environment variables, and tasks.
- A monorepo is a software-development strategy in which the code for a number of projects is stored in the same repository. See for example the monorepo.tools site, first mentioned in Git Rev News Edition #84.
difi is a TUI tool that helps you review and refine Git diffs before you push. Written in Go using the Bubble Tea library, under MIT license.
deff is a TUI tool providing interactive, side-by-side file review for Git diffs with per-file navigation, vertical and horizontal scrolling, syntax highlighting, and added/deleted line tinting. Written in Rust, under MIT license.
ec (easy-conflict) is a terminal Git mergetool with a 3-way TUI and Neovim integration. Written in Go, under MIT license.
Maiao: Gerrit-style code review workflow for GitHub. Maiao brings the power of stacked pull requests to GitHub, enabling you to break large features into small, reviewable commits where each commit becomes its own PR. Provides a git review command. Written in Go, under MIT license.
- Stacked Pull Requests, also under the name Stacked Diffs, were mentioned in Git Rev News Edition #44, #105, #111 (with links to other editions with other articles, and to related tools), #115. #118, #127, and #128.
- Compare with av, a command-line tool that helps you manage your stacked PRs on GitHub. It was mentioned in Git Rev News Edition #115.
- GitButler, a Source Code Management system designed to manage your branches, also supports stacked branches, which was mentioned in Git Rev News Edition #118.
Diffs, aka @pierre/diffs, is an open source diff and file rendering library built on the Shiki syntax highlighter. It supports split (side-by-side) or stacked (unified diff) layout, different diff highlight styles, in-line highlighting, wrapping, and line numbers. Includes an annotation framework for injecting comments and annotations, and more. Written in TypeScript, under Apache 2.0 license. Intended for use in web applications. Diffs is in early active development—APIs are subject to change.
- Compare with diff2html (repo on GitHub), a pretty diff to HTML JavaScript library: diff parser and pretty HTML generator. Written in TypeScript, under MIT license. Provides diff2html-cli, used by, among others, Ungit, Diffy, git-explorer, Simple Git, git-tabular-diff. diff2html was first mentioned in Git Rev News Edition #98, and diff2html-cli in Git Rev News Edition #14.
Gitnuro is a multiplatform Git client, based on JetBrains Compose and JGit. Written in Kotlin, under GPL 3.0 license.
RelaGit - the elegant solution to graphical version control, is a multiplatform Git GUI written in TypeScript. Under LGPL 3.0 license. RelaGit is in early beta stage.
SourceGit is an open-source Git GUI client that supports Windows, macOS, and Linux. Includes built-in conventional commit message helper, and support for using AI to generate commit messages. Written in C#, using the Avalonia cross-platform UI framework, under MIT license.
git-toolbelt is a suite of useful Git commands that aid with scripting or every day command line usage. Written in shell, under BSD-3-Clause license.
- See Git power tools for daily use by Vincent Driessen, the author of git-flow (2018).
sqldef is a CLI tool for diffing two SQL schemas. You can use it to manage the migration of RDBMSs using regular SQL DDLs. Supported databases: MySQL, MariaDB, TiDB, PostgreSQL, SQL Server, and SQLite3. Written in Go, under MIT license (for everything except parser, which is under Apache 2.0 license). Compare with:
- sqldiff.exe, a command-line utility program (Windows binary) that displays content differences between two SQLite databases, mentioned in Git Rev News Edition #87.
- pg-diff, a PostgreSQL schema and data comparing tool written in JavaScript, mentioned in Git Rev News Edition #108.
- git-sqlite, a custom diff and merge driver for SQLite, mentioned in Git Rev News Edition #127.
Fresh File Explorer is a VS Code file explorer which shows only recently modified files based on a combination of Git history and your pending changes. Written in TypeScript, under MIT license.
- See also Fresh File Explorer - vscode extension for navigating recent changes by Frederik Hudák on DEV.to.
Git Remote Color is a VS Code extension that automatically colors your VS Code workspace based on the git remote URL: every repository gets its own unique, consistent color. Inspired by the Peacock extension, but fully automatic using a deterministic hash of the git remote.
- See also VS Code Git Remote Color by Justin Poehnelt on his blog.
commit-prophet is a command line tool that predicts which files are more likely to have bugs using Git history patterns and co-change analysis. Written in Python, under MIT license.
Majutsu provides a Magit-style interface for Jujutsu (jj), offering an efficient way to interact with JJ repositories from within Emacs. Primary project license is GNU GPL v3 or later, but it was previously distributed under MIT license terms.
The Missing GitHub Status Page is a third-party service that tracks 90 days uptime; created because GitHub stopped updating its GitHub Status page with aggregate uptime numbers.

Releases

Git 2.53.0
Git for Windows v2.53.0(1)
GitLab 18.9.1, 18.8.5, 18.7.5, 18.9, 18.8.4, 18.7.4, 18.6.6, 18.6.2, 18.7.1, 18.8.1, 18.8.3, 18.7.3, 18.6.5
Gerrit Code Review 3.11.9, 3.12.5, 3.13.3, 3.13.4
GitHub Enterprise 3.20.0, 3.19.2, 3.18.5, 3.17.11, 3.16.14, 3.15.18, 3.14.23
GitKraken 11.9.0
GitHub Desktop 3.5.5
Sourcetree 4.2.17
Git Cola 4.17.1
GitButler 0.19.3, 0.19.2
Sublime Merge Build 2123
Tower for Mac 15.1
Tower for Windows 11
git-flow-next 1.0

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Bruno Brito, Michael Ryzhikov and Shreyansh Paliwal.

Git Rev News Edition 131 (January 31st, 2026)

chriscool — Sat, 31 Jan 2026 11:06:51 +0000

Git Rev News: Edition 131 (January 31st, 2026)

Welcome to the 131st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of December 2025 and January 2026.

Discussions

Support

Would it make sense to add a commit.signOff config?

Stefan Haller started the discussion by asking if it would be appropriate to add a commit.signoff configuration variable. He observed that while many Git commands, such as merge, cherry-pick, and revert, accept the --signoff argument, only format-patch has a corresponding configuration to enable it for all invocations. Stefan found it reasonable for users to want a “Signed-off-by” trailer added automatically to every commit they make. This question was prompted by his work on the Lazygit project, which already includes such a configuration and had received a feature request to extend its behavior to the revert command.

The “Signed-off-by” trailer is a formal certification that the contributor has the right to submit the work under the project’s license, often associated with a Developer Certificate of Origin (DCO). While widely used in open-source projects to maintain a legal paper trail, its use in closed-source environments is less common.

Carlo Marcelo Arenas Belón replied to Stefan, noting that a similar topic had been discussed recently where it was argued that sign-offs should be given explicitly rather than automated. Junio Hamano, the Git maintainer, agreed and suggested resurrecting a proposal from 2020 to explicitly document why Git intentionally lacks this configuration. Junio expressed a desire to “save time from potential contributors” who might otherwise put effort into a patch that the community had already reached a consensus against.

Collin Funk supported the idea of documenting the consensus and recommended using the full phrase “Signed-off-by” instead of the abbreviation “SoB” to ensure clarity for all readers. brian m. carlson suggested that the explanation could be placed in the Git FAQ, the manual pages, or both. brian also provided a minor grammatical correction to the initial text proposal.

Junio submitted version 1 of a patch to document the decision. The proposed text explained that automation makes it harder to defend a sign-off’s validity in court, as a person could claim the trailer “was done by inertia without person X really intending to certify what DCO says”. The patch also acknowledged that while format.signoff exists, it is considered a “historical mistake” that should not be emulated by other commands.

Elijah Newren found the initial draft somewhat difficult to parse and suggested an alternative version with more sentence breaks. Elijah’s draft emphasized that Git avoids automatic sign-offs specifically to “protect the legal and intentional significance of a sign-off”. He also recommended a shorter version for the manual pages that would point users toward a more detailed entry in the FAQ. Johannes Sixt agreed that Elijah’s version was much easier to read and suggested a minor shortening of the final sentences to maintain impact. Johannes also emphasized the importance of leaving a pointer in the manual pages, as users looking for automation features are more likely to check documentation for specific commands rather than the general FAQ.

Junio provided version 2 of the patch, which incorporated Elijah’s and Johannes’s refinements. During the final review, Johannes suggested changing the phrase “pile on more mistakes” to “add more mistakes” to be clearer for non-native English speakers. Junio adopted this change, noting it would be clear for everyone. Kristoffer Haugsbakk also contributed a final polish by suggesting the use of a proper linkgit:gitfaq[7] reference in the manual page. Elijah and brian both confirmed they were satisfied with the final result.

During the discussion there was a clear consensus that Git will not add a global commit.signoff configuration. The creation of permanent documentation in the Git FAQ and manual pages to explain the legal reasoning behind this decision will prevent future contributors from wasting time on a feature that would be rejected.

Other News

Various

A data model for Git (and other docs updates) by Julia Evans on her blog (see comments on Mastodon and on LWN.net announcement).
SQL Server Management Studio 22 Git Integration by Daniel Calbimonte on MSSQLTips.

Light reading

Diff Algorithm Spelunking by Dachary Carey.
- See also Difftastic, a structural diff tool that understands syntax, first mentioned in Git Rev News Edition #86, and Delta, a syntax-highlighting pager for git, diff, and grep output, first mentioned in Git Rev News Edition #86.
Git Rebase for the Terrified by Aaron Brethorst on Brethorsting Blog.
I made my own git by Tony Strømsnæs on his blog. As it was created with the goal of improving the author’s understanding of Git, it is intentionally made not compatible with Git: it uses SHA-256 instead of (current) SHA-1, and zstd instead of zlib. The example code is written in Rust.
- The Build your own Git section of build-your-own-x lists a few articles about reimplementing parts of Git functionality. Mentioned in Git Rev News Edition #40.
- Write yourself a Git! by Thibault Polge is an attempt at explaining the Git version control system from the bottom up by reimplementing it in Python. Mentioned in Git Rev News Edition #49.
git-pkgs: explore your dependency history by Andrew Nesbitt on his blog.
Git’s HTTP server side design does not scale: a small rant about CGI. Written by Xe Iaso on their blog.
Tracking kernel development with korgalore by Konstantin Ryabitsev on his blog. TLDR: use korgalore to bypass mailing list delivery problems. (See also comments on LWN.net.)
My first 20,000 curl commits by Daniel Stenberg on his blog.
GitOps with ArgoCD feels like the right abstraction by Nick Scialli on his blog.
Bob and Alice: a git patch love story by cybrkyd (Just another Cyber Kid).
Allowlist for .gitignore by Hugues Morisset (izissise) on his blog. Describes a dedicated script to generate the allow-list based .gitignore file effectively to used with a monorepo.
On git show by Tony Strømsnæs on his blog, about the use of git show <revision>:<path>.
How to sync files between two local machines using Git by Bobby Jack on How-To Git.
Manage Diagrams in AsciiDoc (with PlantUML) on GitHub (using a build script) by Lorna Jane Mitchell on LornaJane Blog.
- See also Include diagrams in your Markdown files with Mermaid (2022) by Martin Woodward & Adam Biagianti on GitHub Blog, mentioned in Git Rev News Edition #84.
Maintaining shadow branches for GitHub PRs by Fangrui Song (MaskRay). The goal is to be able to see clean diffs between base and feature branch, even though the underlying commits were rewritten, and the base moved ahead.
Post-Agentic Code Forges, by Son Luong Ngoc (sluongng) on Son’s Substack.
- See also Getting AI to Work in Complex Codebases.
Abandon Git LFS because AI Agents by Justin Poehnelt (jpoehnelt) on his blog (includes description on how to use git filter-repo to migrate from Git LFS to standard Git).
How I use Jujutsu by Abhinav Sarkar on their blog.
- Jujutsu (jj) is a Git-compatible version control system, written in Rust, which was first mentioned in Git Rev News Edition #85.
How GitHub monopoly is destroying the open source ecosystem by Lionel Dricot (Ploum).
Moving from GitHub pages to Codeberg pages by Florian Kotthoff on his Hugo & PaperMod powered blog.
Showcasing my Git repositories on the web (by creating a static site with GitGen, where everything is generated ahead of time) by cybrkyd.
- Compare Gitmal, a static page generator for Git repositories, mentioned in the previous edition.
This tool (pgit) turns any Git repo into a private, offline “GitHub” website by Bobby Jack on How-To Geek.
Git Brag: Highlight and Share Your Open Source Contributions by Robert Hafner on his tedious ramblings blog.
Your GitHub Contribution Graph Means Absolutely Nothing - And Here’s Why by Sylwia Laskowska on DEV.to.
Git forge opinions: GitHub, GitLab, Gitea, Sourcehut (2022) by Cadence on cadence’s website.

Git tools and sites

forgeperf.org - Software Forge Performance Index. Reports generated with Lighthouse, originally updated weekly, last update February 7, 2024. Created and maintained by the SourceHut forge.
Mirror to Codeberg: a central place of information about mirroring repos to Codeberg. Includes some thoughts about why one would want to switch from GitHub or GitLab, or at least have a second place for your code: a mirror that’s contributable, with links to other articles.
git-natural-api is a lightweight git HTTP client for fetching repository data without cloning. It uses /git-upload-pack custom calls to get access to file trees, commit history or individual objects. Written in TypeScript, provides a JavaScript/TypeScript API. Can be used in browser, using Bun, Deno, or Node.js. No license provided.
Grasp (Git Relays Authorized via Signed-Nostr Proofs) is a distributed, protocol-first approach to hosting Git repos. You pre-authorize pushes via signed Nostr events, then any compliant server can host your repo. ngit-relay is a Grasp reference implementation that uses a Dockerized stack: nginx, git-http-backend and a Khatru relay.
- Compare Tangled, a social-enabled Git collaboration platform built on top of the AT Protocol (which is behind the BlueSky microblogging federated social media service). First mentioned in Git Rev News Edition #125, then in #126, and #128.
- Compare Radicle, an open source, peer-to-peer code collaboration stack built on Git, first mentioned in Git Rev News Edition #49, and many times since; most recently in #126.
- There is also gitstr (git str), a tool to send and receive Git patches over Nostr, using NIP-34 (mentioned in Git Rev News Edition #109).
- Compare git-ssb (see the git-ssb-intro guide), a decentralized Git repo hosting and issue tracking on Secure-ScuttleButt (SSB) (mentioned in Git Rev News Edition #26 and #40).
- Contrast with ForgeFed (formerly GitPub), a federation protocol for software forges (an ActivityPub extension), mentioned in Git Rev News Edition #69.
The Game of Trees Hub is a transparently funded Git repository hosting service. Its infrastructure is based on OpenBSD and Game of Trees.
- Game of Trees (Got) is a version control system developed by and for OpenBSD developers, which wants to remain on-disk compatible with bare Git repositories. Mentioned in Git Rev News Edition #54.
keifu (系譜, /keːɸɯ/) is a terminal UI tool that visualizes Git commit graphs. It shows a colored commit graph, commit details, and a summary of changed files, and lets you perform basic branch operations. Written in Rust, under MIT license.
git-com is a TUI tool for creating structured commit messages that’s easy to configure for each project. Written in Go, under MIT license.
Git Brag is an open source web application (or CLI) that creates a simple report of the contributions you’ve made to open source projects on GitHub (it requires logging with GitHub to create the report). Written in Python, under MIT license.
GitGen is a lightweight static website generator for local Git repositories written in Python. It scans a directory of Git repositories and produces a navigable, self-contained HTML website similar in spirit to cgit or GitWeb, but without any server-side dependencies. The generated site includes a repository index, per-repository README rendering, file listings, commit history, and detailed commit views with diffs. Under GPLv3 license.
- Compare Gitmal, a static page generator for Git repositories, written in Go, under MIT license. It was mentioned in Git Rev News Edition #130.
pgit is static site generator for git repos. Demo at https://git.erock.io/. Written in Go, under MIT license.
GAH! is your friendly neighborhood good helpful archiver. It archives GitHub issues and pull requests, and can create a static site from archives. Written in Python, under BSD license (Simplified BSD License).
tokendiff is a Go library and CLI for token-level diffing with delimiter support. Tokendiff uses a histogram diff algorithm that groups semantically related changes together, producing more readable output than traditional Myers-based approaches for complex structural changes. It builds on diffx, a Go implementation of Myers diff. Under MIT license.
CleanDiff is a graphical diffing tool that shows you what’s changed on a word level, instead of a line level. It uses the tokendiff library to find semantically relevant changes, and wraps them in a nice UI and easy Git integration. Written in Go and JavaScript, under MIT license.
patch-hub is a terminal-based user interface (TUI) designed to simplify working with software patches sent through mailing lists in Linux-related development. It provides an efficient way to navigate and interact with patches archived on lore.kernel.org, specifically for the Linux kernel and adjacent projects. Written in Rust, under GPL-2.0 license.
Korgalore is a tool for feeding public-inbox Git repositories, like lore.kernel.org, directly into mail targets (Gmail, JMAP, IMAP, or local maildir) as an alternative to subscribing. It provides a workaround for Gmail’s notorious hostility to high-volume technical mailing list traffic. Written in Python, under GPL-2.0 license.
git-pkgs provides a git subcommand for tracking package dependencies across Git history. It analyzes your repository to show when dependencies were added, modified, or removed, who made those changes, and why. Builds on bibliothecary, the manifest parsing library behind ecosyste.ms. Written in Go (originally in Ruby), under MIT license.

Releases

Git 2.53.0-rc2, 2.53.0-rc1, 2.53.0-rc0
Git for Windows v2.53.0-rc2(1), v2.53.0-rc1(1), v2.53.0-rc0(1)
GitHub Enterprise 3.19.1, 3.18.4, 3.17.10, 3.16.13, 3.15.17, 3.14.22
GitLab 18.8.2, 18.7.2, 18.6.4, 18.8.1, 18.8, 18.7.1, 18.6.3, 18.5.5
Gerrit Code Review 3.11.8, 3.12.4, 3.13.2
GitKraken 11.8.0
Sourcetree 4.2.16
Garden 2.5.1, 2.5.0
Git Cola 4.17.0
GitButler 0.18.7, 0.18.6
Kinetic Merge 1.14.0
git-credential-oauth 0.17.2, 0.17.1, 0.17.0

Credits

Git Rev News Edition 130 (December 31st, 2025)

chriscool — Wed, 31 Dec 2025 11:06:51 +0000

Git Rev News: Edition 130 (December 31st, 2025)

Welcome to the 130th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of November and December 2025.

Discussions

Support

git-2.51.0: Fetching tags does not work

Last September, David Bohman reported a regression in Git 2.51.0 where git fetch --tags failed to update tags in a bare repository. He noted that the command output indicated tags would be updated, but they were not actually added to the repository. Reverting to version 2.50.1 resolved the issue.

Junio Hamano, the Git maintainer, attempted to reproduce the issue using a simple bare clone setup but was unsuccessful, suggesting that David needed to narrow down the specific conditions.

In early November, David returned to the thread reporting that the issue persisted in Git 2.51.2. He provided a specific reproduction case involving a bare clone of the bind9 source repository. The output showed that one tag update was rejected (with a would clobber existing tag error), and consequently, all other valid new tags (v9.18.41, etc.) failed to appear in the repository, despite being listed as “new tag” in the output. The command exited with status code 1.

Randall S. Becker suggested using git fetch --tags --force to clear the situation. David Bohman replied that while he could reproduce it locally, the key behavioral change was that prior to version 2.51, Git would fail regarding the conflicting tag but still insert the non-conflicting ones.

Chris Torek identified the new reference transaction system introduced in recent versions as the root cause. He noted that the behavior had shifted to “all or nothing” (either all tags get updated, or none do) and questioned which behavior was actually buggy. David Bohman argued that this was a risky change for a mature tool and noted that the diagnostic messages were misleading because they reported success for tags that were not actually inserted.

Karthik Nayak confirmed he could reproduce the issue and attributed it to transaction reference updates.

Karthik submitted version 1 of a patch to fix the issue. He explained that commit 0e358de64a (fetch: use batched reference updates, 2025-05-19) introduced batched reference updates for git fetch. When fetching references, updates are added to a transaction. However, specifically when fetching tags, if a conflict occurs, the function fetch_and_consume_refs() returns an error code immediately. This caused the code to jump to the cleanup section, skipping the commit of the transaction entirely, and thus discarding even valid updates.

The proposed fix involved extracting the transaction commit logic into a new function, commit_ref_transaction(), and ensuring it is called even when an error code is returned, provided the fetch is not atomic.

Eric Sunshine reviewed the patch, asking why the test code was wrapped in subshells and suggesting that ! should be replaced with test_must_fail. Karthik agreed to these changes.

Justin Tobler reviewed the code, agreeing with the logic. He suggested adding a comment to commit_ref_transaction() to distinguish it from ref_transaction_commit() and asked if the return value of this new function should be checked.

Karthik submitted version 2 of the patch. This version added comments, removed subshells from tests, and extended the fix to the backfill_tags() function.

Patrick Steinhardt reviewed version 2. He questioned the commit message’s mention of the deprecated “branches/” format in relation to tag backfilling. Karthik replied, clarifying that after re-reading the code, he understood that backfilling happens when the user does not specify --tags or --no-tags, confirming Patrick’s understanding.

Patrick noted that the code now had three different call sites committing the transaction and felt it was “somewhat fragile.” Justin pointed out that the return code of commit_ref_transaction() was being ignored in the new implementation. Karthik agreed to check the return value.

Karthik submitted version 3 of the series. He split the changes into two commits: one for extracting the logic and one for the fix. He also moved the commit logic into the cleanup section to avoid calling it at every failure point.

Patrick reviewed version 3. He suggested using goto out in commit_ref_transaction() for better readability. He also asked for clarification on why the condition retcode > 0 was safe in the cleanup section, specifically regarding prune_refs(). Karthik replied, explaining that prune_refs() creates its own internal transaction, but later realized he was mistaken about the timing and promised to verify.

Karthik submitted version 4. This version simplified the code and changed the check from retcode > 0 to just retcode.

Patrick pointed out that the commit message regarding prune_refs() behavior change seemed incorrect because no transaction exists at that stage. Karthik verified this and confirmed there is no change for prune_refs().

Karthik submitted version 5 with corrected commit messages and better test cleanup.

Junio reviewed version 5 and identified a remaining issue. He noted that while the patch fixed the transaction commit, jumping to the cleanup label early meant that subsequent operations (specifically commit_fetch_head(), set_upstream(), and setting remote HEADs) were still being skipped when errors occurred. He argued that in non-atomic fetches, these should still run. Karthik agreed and proposed a fix to only jump to cleanup if --atomic was used.

Karthik submitted version 6, adding a third commit to the series to address the skipped operations regression identified by Junio.

Junio reviewed version 6. He liked the tests but warned against using touch to create files due to timestamp issues and noted a missing test case for --set-upstream on a successful fetch. Karthik agreed to fix these.

Karthik submitted version 7, removing touch and adjusting the test prerequisites.

Eric reviewed the tests in version 7, asking if ! test -f should be test_path_is_missing. Junio suggested using rm -f FETCH_HEAD before the test to ensure it is actually created during the run, and inspecting the file content to verify what was recorded. Karthik agreed.

Karthik submitted version 8. This version verified the content of FETCH_HEAD and used test_path_is_missing.

Junio commented that the series looked good. Patrick pointed out a tiny grammar nit (“eventhough”) and asked if the shell syntax >file used in the test was compatible with all systems, noting : >file is more typical. Karthik replied that existing tests use the shorter syntax, so it should be fine.

The small patch series was eventually merged, and should be part of Git 2.53.0 that should be released at the latest towards the beginning of February 2026. With this version, not only the transaction logic will be fixed, but related regressions regarding post-fetch operations (like updating FETCH_HEAD) will also have been identified and resolved.

Developer Spotlight: Lucas Seiki Oshiro

Who are you and what do you do?

My name is Lucas Oshiro, I’m one of the three GSoC ‘25 participants working on Git. I’m from São Paulo, Brazil, and I hold bachelor and master degrees in Computer Science from the University of São Paulo. I don’t have only one specific interest in programming topics, I enjoy several different topics, like lower-lever C code (like we do for Git), FP languages (especially Haskell), play with network simulators, data analysis, operating systems, databases and so on.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your GSoC project?

Well, it’s a long story… I think that it dates back to 2017, in a Computer Networks assignment at my university. My partner in that assignment was Matheus Tavares, who participated in GSoC ‘19 on Git. At the time, we needed to study a vulnerability and how it was fixed. We chose CVE-2017-1000117, which was a vulnerability in Git. That was my first time reading Git source code.

Two years later, I was a member of a group focused on contributing to Free/Open-Source software at my University. I sent a patch to Git at the time, but I needed to focus on other stuff and I couldn’t finish it.

After that, I started to work as a back-end software engineer and witnessed several Git-related problems. My two previous experiences with Git’s source code made me want to understand what was happening and delving into its internals, so I could help other developers from my company when something unexpected happened with Git.

This way, Git always felt like the right choice.
How do you feel your contribution has impacted the Git community or the broader open source ecosystem?

My GSoC project was to create the new command git repo info). It was released in Git 2.52.0 and, like many other new Git features, I expect it will take some time to be widely adopted, since it’s only available in bleeding-edge repositories. But I expect that it will be useful for forges, CIs, local tools, scripts, and other tools that depend on Git.
Is there any aspect of Git that you now see differently after having contributed to it?

I can’t think of anything that I see differently after GSoC, but my previous contacts with Git’s source code made me realize the importance of having a good commit history with good commit messages. It also made me understand how powerful Git is as a debugging and searching tool.
How do you balance your contributions with other responsibilities like work or school?

This year, I was more focused on finishing my master’s research and I didn’t have too many conflicts with GSoC, so I could focus on my master’s when my patches were under review. However, I must admit that one of the reasons that I didn’t apply to GSoC before was that, here in Brazil, we typically have final exams in June, which makes it hard to balance them with something else.
Can you share how GSoC helped enhance your technical and non-technical skills (like communication, project management, etc.)?

I see Git as a product created by developers, for developers, and I think that here we sometimes need to do the work that in other contexts would be done by product owners and designers. I felt that especially during code reviews, which were often more focused on product and design decisions rather than the code itself. I had to learn how to discuss these kinds of decisions, always aiming to do what is best for Git and its users.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

I think that the biggest challenge was the complete redesign of git repo info during the GSoC period, which made me re-write it from scratch several times. I think this was a consequence of my previous answer and that this challenge was solved itself.
Have you thought about mentoring new GSoC / Outreachy students?

Yes, it would be very nice!
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Git is amazing and I think we all agree that it makes the programmers’ lives easier. It would be great if we had a GUI wrapping Git but targeting non-technical users.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Perhaps commands that accumulate responsibilities, like git checkout, git reset and git rev-parse. They make sense from the Git perspective, but I think they are confusing from the users’ perspective.
What upcoming features or changes in Git are you particularly excited about?

Some that come to my mind are:
- Patrick Steinhardt’s new git history command: rewriting history is essential to keep the repository sane and useful as a data storage, if done correctly. Currently we do that through interactive rebase but I think it can be intimidating for less experienced users. Jujutsu proposes a more straightforward way to do that, and it’s nice to see Patrick bringing it to Git.
- Justin Tobler’s new git repo structure command: of course I’m interested in this subcommand since it is the sibling of my GSoC project. But it’s not only because of that: a Git repository is a very rich source of information and git repo structure will be a powerful tool to retrieve it.
- Julia Evans’s contributions to documentation: Julia has been producing high-quality content about several programming topics for years. I’m happy to see Git being documented by someone so committed to spreading knowledge and who knows how to explain advanced concepts using a simple language.
What is your favorite Git-related tool/library, outside of Git itself?

I use delta a lot, I like the way it highlights diffs. Other tools that I find interesting are Jujutsu and Magit, but I don’t use them too much.
What is your toolbox for interacting with the mailing list and for development of Git?

I like desktop mail clients, but I don’t have a strong preference. On Linux, I use Thunderbird. On Mac, I use Apple Mail. I also have some GMail filters for classifying the messages (patches, What’s Cooking and Rev News announcements).

However, those mail clients don’t have code syntax highlighting, and it’s hard to read the patches inside them. For that purpose, I use patch-hub, a TUI for reviewing patches from kernel mailing lists (including Git).
How do you envision your own involvement with Git or other open source projects in the future?

There are some things I want to finish in git repo info, and I still send patches for it. I enjoyed contributing to Git and I don’t want to stop here.

Outside Git development, I’ll give an advanced course on Git next month. It will be a great opportunity to share what I’ve learned here with other people.
What is your advice for people who want to start Git development? Where and how should they start?

Read the Git Internals chapter from Pro Git, follow everything described in Hacking Git, and work on a microproject.
Would you recommend other students or contributors to participate in the GSoC, Outreachy or other mentoring programs, working on Git? Why? Do you have advice for them?

Yes. I mean, I’ve already recommended some people from my university to apply to GSoC or Outreachy on Git and gave some tips to them. Some of them have already sent patches that were accepted.

Other News

Various

Debian’s git transition by Ian Jackson on diziet’s journal on Dreamwidth. The main goal of the transition is to make it so that everyone who interacts with Debian source code should be able to do so entirely in git.
Git’s New Era: What Git 2.52 and the Road to Git 3.0 Mean for Developers in 2026 by Faisal haque on Medium. Free access provided via Faisal haque’s Friend Link.
- See also What’s new in Git 2.52.0? on GitLab Blog and Highlights from Git 2.52 on GitHub Blog, mentioned in the previous edition of Git Rev News.
- See also Git Developers Talk About Potentially Releasing Git 3.0 By The End Of Next Year on Phoronix, mentioned in Git Rev News Edition #128.
- There is also BreakingChanges: Git 3.0 document in the Git documentation.

Light reading

Package managers keep using git as a database, it never works out by Andrew Nesbitt on his blog.
Git Commit Count Percentile Stats, Annual Days Active from 878,592 Dev-year Data Points by Bill Harding, a first-party research by GitClear.
Fizzy Design Evolution: A Flipbook from Git by Rob Zolkos on his blog; includes the generated video.
Comparing the homepage-claims of popular Git hosting providers by Sebastian Gumprich on zufallsheld - a tech blog.
Are people migrating away from GitHub?, a short post (with examples) by Rob O’Leary on his blog.
GitHub Actions Has a Package Manager, and It Might Be the Worst by Andrew Nesbitt on his blog.
The Pain That Is GitHub Actions by Gerd Zellweger on feldera blog.
Migrating from GitHub to Codeberg by Robin Métral on his blog.
Migrating my code to Codeberg and GitHub → Codeberg: my experience by Eldred Habert on ISSOtm’s warehouse blog.
Migrating Dillo from GitHub by Rodrigo Arias Mallo on Dillo project blog.
Migrating from GitHub to Codeberg by Andrew on Zig Language News.
How Do Git Remotes Work? And How Do I Self-host My Own? What it takes to create the simplest, barest self-hosted Git remote, and learn stuff about Git in the process. Post by Charles Féval on his blog.
Guarding My Git Forge Against AI Scrapers by ~lymkwi (lux) on VulpineCitrus blog. The forge in question is a self-hosted Forgejo instance.
Rethinking Git Pre-Commit Hooks by Mathieu Larose on his blog.
pre-commit hooks are fundamentally broken by Jynn Nelson (@jyn) on the website of jyn.
- See also Discussion of the Benefits and Drawbacks of the Git Pre-Commit Hook in Git Rev News Edition #128.
- The Git Hooks website gives an example of using pre-commit hook to check the commit message for spelling errors;
  the pre-commit.sample provided with Git checks for non-ASCII characters in filenames (and can be configured to be turned off with hooks.allownoascii).
- There are various tools that help managing pre-commit hooks, like pre-commit (first mentioned in Git Rev News #45) and prek (first mentioned in Git Rev News #127).
Fixing the “Ghost Folder” in GitHub: Converting a Broken Submodule to a Normal Folder by Raziq Din on DEV.to.
Shooting myself in the foot with Git by accident by Chris Siebenmann on CSpace blog. The Git error in question was “error: fetching ref refs/remotes/origin/master failed: incorrect old value provided”.
Tracking renamed files in Git and Use ‘git mv’ to record filename case changes in Git by Ole Begemann on his blog.
Branch Protection Rules vs Rulesets: The Right Way to Protect Your Git Repository by Piyush Gaikwad on DEV.to. The main idea is to use Branch Protection Rules for long lived branches, and Branch Rulesets for short lived branches, defining rules before branches are created.
magit-insert-worktrees improves status buffers by Huon Wilson on his “Huon on the internet” blog.
- The Magit package for interfacing to Git within the Emacs editor was first mentioned in passing in Git Rev News Edition #6; among other mentions there was Emacs and Magit article on LWN.net in Git Rev News Edition #30.
Archiving git branches as tags with a git alias. Blog post by octavore (the author of Delta, a command-line diff tool) on “et cetera”.
Building a Meta-Logger: Tracking My Work Across GitHub, Codeberg, and Bitbucket Using Go by Nimai Charan on DEV.to.
why i think jj-vcs is worth your time on Schpet’s Notebook.
- Jujutsu (jj) is a Git-compatible version control system written in Rust, which was first mentioned in Git Rev News Edition #85.
- See also Should I Switch From Git to Jujutsu (mentioned in Git Rev News Edition #129) and Switch to Jujutsu already: a tutorial (mentioned in Git Rev News Edition #128).
From Zero to GitHub: Starting A New jj (Jujutsu) Repo by Josh Branchaud on VisualMode.
30 Years of <br> Tags: Three decades of making things on the internet. Includes the introduction of Git, GitHub, and the GitDevOps (push to publish) workflow. Post by Christoffer Artmann on his blog.
Free Software Needs Free Tools by Benjamin Mako Hill (2010).

Easy watching

Magit, fzf, and ast-grep demo by Eliot (@saltycrane) on SaltyCrane Blog. The video on YouTube is 12:40 minutes long.
Git & GitHub Crash Course for Beginners by Beau Carnes on freeCodeCamp. The video on YouTube by freeCodeCamp.org and logicBase Labs is 1:21:19 hours long.

Git tools and sites

check-projects is a fast, cross-platform CLI tool (with TUI interface) to check the Git status of multiple projects organized by categories. Written in Go, under MIT license.
repos is an interactive CLI tool for managing multiple Git repositories. Written in TypeScript (with pre-built binaries), under MIT license.
Patchy 🩹 is a CLI for generating and applying patches to Git repositories.
- Similar in a way to Stacked Git, StGit for short, first mentioned in Git Rev News Edition #17, to a lesser extent to patchwork, first mentioned in Git Rev News Edition #20, or to git-revise, first mentioned in Git Rev News Edition #54 - where you can find links to other similar tools.
git-pw is a tool for integrating Git with Patchwork. Written in Python, under MIT license.
git-forge is a simple CLI tool for basic interactions with issues and pull requests across GitHub, GitLab, Gitea, and Forgejo. (Re)Written in Rust, under MIT license.
See also git-forge: Faster Issues and PRs From Your Terminal blog post by Anh Tuan Le.
gtr - Git Worktree Runner by the CodeRabbit team is a portable, cross-platform CLI for managing Git worktrees with ease, with editor and AI tool integration. It automates per-branch worktree creation, configuration copying, dependency installation, and workspace setup. Written in Bash, under Apache 2.0 license.
See also A Better Way to Run Git Worktrees Finally! by Julio Daniel Reyes on DEV.to, with video on YouTube [5:52].
- There is also Worktree Manager (wtm) mentioned in Git Rev News Edition #128, and wtp (Worktree Plus) mentioned in Git Rev News Edition #125.
Git Pow is an open-source, cross-platform Git client. It implements conditional strategies to handle larger repositories, showing image previews to visualize what changed, and grouping commits by month/year, among other features. Written in Rust and JavaScript using the Tauri framework. Under GNU GPL v3.0 license.
Git Repository Squirrel 🐿️ (reposquirrel) is a comprehensive Git repository analytics tool that provides detailed insights into developer contributions, subsystem ownership, and codebase evolution over time. Written in Python (using the Flask library) and JavaScript, under CC-BY-NC-SA 4.0 license. Demo and Docker image available.
Gitmal is a static page generator for Git repositories. Gitmal generates static HTML pages with files, commits, code highlighting, and Markdown rendering. Written in Go, under MIT license.
Git Rewind is a GitHub App that provides Your GitHub year in review — with privacy-first, read-only access (using fine-grained permissions). Written in TypeScript, under MIT license. Available at git-rewind.vercel.app.
Critic is a code review system. It is a web application written in Python, tightly integrated with Git. Under Apache 2.0 license.
See also Meet Critic: Code Inspection System in Opera Software on Sudo Null IT News.
Buggy: Fast and simple bug tracker. The buggy program compiles a set of issues written in Markdown into HTML pages suitable to be read from a web browser. It is intended to be used alongside a version control system (VCS) like Git to track changes in the issues. Written in C, under MIT license.
Today I Learned: Git by Josh Branchaud, under MIT license.

Releases

libgit2 1.9.2
GitHub Enterprise 3.19.0, 3.18.3, 3.17.9, 3.16.12, 3.15.16, 3.14.21, 3.18.2, 3.17.8, 3.16.11, 3.15.15, 3.14.20
GitLab 18.7, 18.6.2, 18.5.4, 18.4.6
GitKraken 11.7.0
Sourcetree 4.2.15
Garden 2.4.0, 2.5.0
Git Cola 4.17.0
GitButler 0.18.3, 0.18.2
Sublime Merge Build 2121
Kinetic Merge 1.13.2, 1.13.1, 1.13.0, 1.12.2, 1.12.1, 1.12.0

Credits

Git Rev News Edition 129 (November 30th, 2025)

chriscool — Sun, 30 Nov 2025 11:06:51 +0000

Git Rev News: Edition 129 (November 30th, 2025)

Welcome to the 129th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of October and November 2025.

Discussions

Support

[Bug report] git cherry-pick silently ignores error whereas git apply fails for hunk apply

Bhavik Bavishi filed and sent a bug report to the mailing list. Running git cherry-pick failed to apply some changes but didn’t report any error. On the contrary, when creating a patch using git format-patch from the same commit and applying it using git apply --verbose, the latter command also failed to apply the same changes but errored out. It seemed that there shouldn’t be such a behavior discrepancy and that git cherry-pick should have reported an error, too.

Johannes Sixt suggested using git apply --3way to apply the patch. He was interested not only in the success or failure of the command, but also in the end result of applying the patch. Was that end result similar to the result of git cherry-pick or different?

Bhavik reported back that indeed git apply --3way succeeded and produced the same end result as git cherry-pick. Even though it looked like git cherry-pick worked as expected, that still seemed a strange behavior.

Johannes Sixt replied that a merge strategy is used by both git cherry-pick and git apply --3way. Unlike a simple patch application, a merge strategy is intelligent enough to detect if a change has already been applied. He illustrated this with an example where text repeats in a file, but only specific instances are modified.

In the meantime, Chris Torek also replied to Bhavik providing a wealth of explanations. He explained that git apply works with a patch, which is essentially a “we expect the file looks like this” instruction. If the file doesn’t match the expected context lines exactly, the patch fails.

In contrast, git cherry-pick performs a 3-way merge. It locates a “common base version” (the ancestor), compares it to “Ours” (current branch), and “Theirs” (the commit being picked) . If the merge logic sees that “Theirs” introduces a change that “Ours” has already made, it silently discards the duplicate change rather than erroring out. This confirms that the command was working as intended, using the full history to resolve what looked like a conflict to the simpler git apply tool.

Bhavik thanked Chris for the helpful explanations.

Developer Spotlight: Ayush Chandekar

Editor’s note: This edition features a retrospective interview with a contributor who contributed to Git through a mentoring program. We hope the reflections shared by the GSoC contributor will provide an insightful perspective that benefits the community. As always, we welcome your thoughts and feedback!

Who are you and what do you do?

I am Ayush Chandekar, a GSoC 2025 alumnus under Git, my project was titled ‘Refactoring in order to reduce Git’s global state’. Currently I am an engineering undergraduate at IIT Roorkee, I consider myself to be a jack of all trades, with interests ranging from low-level programming to game development, cybersecurity, and blockchain. I am also a member of SDSLabs, a student run technical club at my university which also focuses on making software and tech accessible for the campus.

As a kid I always enjoyed tinkering with computers and would spend majority of my time on games, but slowly I started enjoying the chance that development gave me to be the one behind the scene, controlling and making stuff which works. My approach is driven by curiosity and a desire to understand how things really function. Whenever I start learning something new, I naturally end up going deeper and deeper into the smaller, niche details, not because I have to, but because it genuinely fascinates me. I enjoy peeling back the layers, figuring out the underlying mechanisms, and understanding the “why” behind everything I work on. It’s that curiosity that keeps pulling me into new domains and motivates me to keep exploring. Apart from this, for fun, I like to participate in hackathons, GameJams and Cyber security Capture-The-Flag(CTF) competitions. Outside of tech, I enjoy listening to music, brewing coffee, skateboarding, and learning guitar, they help me unwind and keep a balance beyond the screen.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your GSoC project?

I wanted to start my journey of contributing to open source projects. Before that, I was working on small C projects, and that’s when I came across Git. I was immediately drawn to understanding how developers actually work on Git itself. The workflow felt new to me, kind of old-school in a good way, and it definitely took some time to get used to, but I really enjoyed the process. As I dug deeper, I realized how Git’s internals work, and that made me even more curious. The idea that I could learn from such a mature codebase, while also improving a tool used globally, was extremely motivating. It felt like the perfect place to challenge myself, improve my skills, and contribute to a big project.
Is there any aspect of Git that you now see differently after having contributed to it?

It is about how there are so many different commands. Before my GSoC, I was only aware of the usual git push, git pull, git clone, etc. Now, I know many more commands like git bisect, git range-diff, etc. I even understand how some of them work internally. Contributing to Git really opened my eyes to the depth and complexity of the tool.
How do you balance your contributions with other responsibilities like work or school?

Balancing contributions with other responsibilities is a bit challenging. As an undergrad student, I’m involved in various activities at my university, including sports and other commitments, so my schedule gets busy. But whenever I sit down to work or study, I get very absorbed in it, and I often end up spending long stretches of time without even realizing it. That focus helps me make steady progress even with a packed routine.
Can you share how GSoC helped enhance your technical and non-technical skills (like communication, project management, etc.)?

GSoC helped me grow in both technical and non-technical areas. On the technical side, I became much more comfortable reading large codebases, debugging tricky issues, and writing clean, well-structured patches. I also learned the importance of clear and detailed commit messages. On the non-technical side, GSoC improved my communication skills a lot, especially explaining my ideas, asking the right questions, and discussing feedback with the community. It also taught me how to plan my work, break tasks into smaller steps, and manage my time over a long project. Overall, it made me more confident in collaborating in an open-source environment. I would also like to thank my mentor, Christian, for his guidance and patience throughout the project. His feedback played a big role in helping me improve.
What was your biggest takeaway or learning from GSoC that you now apply regularly in your work?

My biggest takeaway from GSoC was the importance of writing clear and detailed commit messages. Before the program, I didn’t pay much attention to how a commit was explained, but contributing to Git made me realise how essential it is. A good commit message not only describes what changed but also why the change was necessary, making it much easier for reviewers and future contributors to understand the context.

Another major learning was understanding how to handle reviews from multiple people. In the Git community, different contributors often suggest different things, and figuring out how to take in all that feedback while still taking ownership of my work was a big shift for me. I learned how to look at each suggestion carefully, understand the reasoning behind it, and decide what improves the patch. It also taught me when to explain my choices and when to adjust my approach. This experience helped me become more confident in iterating on my work and communicating clearly, while staying responsible for the decisions I make.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

There were a few challenges which I faced. Initially, it was getting accustomed to the mailing list workflow as it was new to me. Most of the challenges were making sure that the community accepted your patches. A lot of people reviewed my patches and got different responses. Here, I learnt to take ownership of my patches.
Have you thought about mentoring new GSoC / Outreachy students?

Yes, I’ve definitely thought about mentoring future GSoC students, most likely as a co-mentor. I feel it would be a great way to give back to the community and support newcomers the same way I was supported.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

It would be removing the global state from Git, which was my GSoC project and is also an ongoing effort in the community for the maintainability and modularity of the codebase.
What upcoming features or changes in Git are you particularly excited about?

I’ve been following Patrick’s patch series on git history. I am excited about that feature’s release.
What is your favorite Git-related tool/library, outside of Git itself?

I have heard of Jujutsu, I haven’t tried it yet but it seems cool, other than that sticking to my essentials, GitLab and GitHub.
What is your toolbox for interacting with the mailing list and for development of Git?

I just use Gmail to view and reply mails most of the time. But when it comes to sending patches, I use the good ol’ git send-email. I had set up mutt once, but didn’t use it as much.
How do you envision your own involvement with Git or other open source projects in the future?

I don’t have anything planned out in particular but I do really admire the way my mentor and other contributors in the organisation contribute. Open source is something which basically runs the world, organisations like Git and Linux function because of collective and voluntary efforts; they are what makes the world as it is today, and carrying that forward I want to contribute in a way which makes software accessible to everyone and help build up on these foundational blocks.
What is your advice for people who want to start Git development? Where and how should they start?

Git is an amazing project to learn all aspects of development. It helps you to learn/improve your C and debugging skills. Another important thing is how you get to work with different contributors in the community. You get reviews from everyone which helps you understand different perspectives. To start with, I would suggest going through this page called ‘Hacking Git’ and checking different articles mentioned there along with the Contribution Guidelines. It is quite difficult to decide what to work on initially, as there are no traditional issues as other organizations have. Being active on the mailing list, checking out the ongoing topics might help you decide what to work on. Everyone on the mailing list and discord is very friendly and is always looking forward to help you out, so feel free to ask if you have any doubts :)
Would you recommend other students or contributors to participate in the GSoC, Outreachy or other mentoring programs, working on Git? Why? Do you have advice for them?

As I answered before, it is sometimes difficult to decide what you can work on. I feel that for Git, since projects are already listed on the GSoC and Outreachy pages, it takes away the pain of figuring out where to start. You just need to pick a project that interests you and then spend some time studying it. Other than that, you’re also mentored by someone experienced in Git development, and with their guidance you’re able to follow best practices and learn a lot of new things. These programs really help build confidence, especially when contributing to a large and complex codebase. You also get to improve your communication skills through discussions, reviews, and patch iterations. And most importantly, it opens doors for future contributions, networking, and long-term involvement in open source. My advice would be to learn to be patient with reviews. A lot of people in the community contribute voluntarily, so you may not get reviews on your patches quickly, and that’s completely normal.

Other News

Various

What’s new in Git 2.52.0? by Christian Couder, Patrick Steinhardt, Toon Claes on GitLab Blog. Highlights include git last-modified command, git fast-export and git fast-import signature-related improvements, new and improved git maintenance strategies, a new subcommand for the new git repo to display repository metrics, etc.
Highlights from Git 2.52 by Taylor Blau on GitHub Blog. Mentions the git last-modified command for tree-level blame information, advanced repository maintenance strategies for git maintenance, new subcommands added to git refs, the experimental git repo command, etc.
lakeFS Acquires DVC, Uniting Data Version Control Pioneers to Accelerate AI-ready Data announcement by lakeFS on their Mentions Media page.
- DVC Joins lakeFS: Your Questions Answered! by Jeny De Figueiredo on DVC Blog.
- A Shared Vision for the Future of DVC by Dmitry Petrov on DVC Blog.
- See also “Data Management” section of Awesome MLOps, mentioned in Git Rev News Edition #116. That edition also includes references to DVC and lakeFS, and other similar tools (though the list there is missing Meltano (first mentioned in Git Rev News Edition #42) and Pachyderm (first mentioned in Git Rev News Edition #49).
20 Years of Git, 2 days at GitHub HQ: Git Merge 2025 highlights 🎉 by Lee Reilly on GitHub Blog.
- See also the previous edition of Git Rev News for more links about Git Merge 2025.

Light reading

Version Control in the Age of AI: The Complete Guide by Bruno Brito on Git Tower blog.
Analyzing 10 years of accepted patch series to Git by D. Ben Knoble on his Junk Drawer personal blog.
Mergiraf: syntax-aware merging for Git by Daroc Alden on LWN.net.
- Mergiraf is a merge-conflict resolver that uses a generic algorithm plus a small amount of language-specific knowledge to solve conflicts that Git’s default strategy cannot. It was mentioned in Git Rev News Edition #117.
- The Mergiraf author recommends using the tool together with Difftastic, a structural diff tool that understands syntax, mentioned in Git Rev News Edition #86.
Should I Switch From Git to Jujutsu by Evan Todd on his personal blog.
- Jujutsu (jj) is a Git-compatible version control system written in Rust, which was first mentioned in Git Rev News Edition #85.
- See also Switch to Jujutsu already: a tutorial by Stavros on Stavros’ Stuff, mentioned in the previous edition.
Why Git is the first tool every new developer needs to learn by Graeme Peacock on How-To Geek.
Git for Vibe Coders, just enough to stop Claude from accidentally deleting your code and database. By Abid Ali Awan on KDnuggets.
4 advanced git commands you probably haven’t heard of: git clean, git bisect, git cherry-pick, git revert, by Bobby Jack on How-To Geek.
Setting File Permissions in Git by Tom Vaidyan on his personal blog; though I wonder why he shows the low-level git update-index --chmod=+x <file> “plumbing” command first, instead of the corresponding user-facing git add --chmod=+x <file> “porcelain” command.
Why You Should Be Using Git Worktrees by Conor in Quick Tip on their Random Bits personal blog (it includes their helper gwc, i.e. git worktree create, shell script).
tree-me: Because git worktrees shouldn’t be a chore by Phil Haack on his You’ve Been Haacked blog.
Use skip-worktree to ignore modified files by Brandon Pugh in the “TIL: Today I learned…” section on his blog.
Managing Multiple Projects in One Repository: Submodules, Subtrees, Monorepos & Partial Cloning Explained by Kibet Korir (K-kibet) for Codespear on DEV.to.
Automatically switching Git Identities and SSH Keys on the same machine with the help of includeIf directive in the .gitconfig file, by Enrico Bison (enbis) on DEV.to. See also:
- Splitting SSH and git configs mentioned in Git Rev News Edition #42.
- How to Use Multiple Git Configs on One Computer mentioned in Git Rev News Edition #71.
- How I configure my Git identities mentioned in Git Rev News Edition #117.
- One PC, Multiple Git Configs (This Will Save You Time!) mentioned in Git Rev News Edition #120.
Git: Amend any commit (scripting around git commit --amend, git commit --fixup, and git rebase --autosquash) by Ylan Segal on his “on.code && such” blog.
If You Think YOUR Commit Messages Are Bad, Just Wait… by Sylwia Laskowska on DEV.to, with others providing more examples in comments.
Mistakes I see engineers making in their code reviews by Sean Goedecke on his blog.
Testable Dotfiles Management With Chezmoi by Shunsuke Kitada (北田俊輔), Ph.D. on shunk031.me.
Backing up my repositories to self-hosted Gitea by Igor Kulman on his personal blog.
- Gitea is a Go-based software forge, a fork of Gogs. It was first mentioned in Git Rev News Edition #23.
Fixing Vercel’s ‘Git Author Must Have Access’ Error, which was caused by the way how Vercel handles multiple accounts. Written by Pavlin Gunov (PavlinBG) on his blog.
Running DVC on a SLURM cluster by Dom Miketa on DVC Blog (2024).
- DVC (Data Version Control), an open-source version control system for data science projects, was first mentioned in Git Rev News Edition #23.

Easy watching

How to ensure the Git community is and stays healthy: Emily Shaffer / Patrick Steinhardt & guests on GitButler channel on YouTube [duration: 44:42].

Git tools and sites

gitlogue is a cinematic Git commit replay tool for the terminal, turning your Git history into a living, animated story; with realistic typing animations, syntax highlighting, and file tree transitions, transforming code changes into a visual experience. Written mainly in Rust, under ISC License.
PyDriller is a Python framework that helps developers in analyzing Git repositories. With PyDriller you can easily extract information about commits, developers, modified files, diffs, and source code. Written in Python, under Apache 2.0 license.
tree-me is a minimal git worktree helper that leverages Git’s native capabilities. It uses Git-like subcommands and follows conventions so you don’t have to think: auto-detects the repository name from your Git remote, auto-detects the default branch, organizes by repo, provides tab completion, etc. Single bash script, part of haacked dotfiles. No license.
- See also Worktree Manager (wtm), a fast, modern CLI tool for managing Git worktrees in bare repositories, mentioned in Git Rev News Edition #128.
Spelungit is a Model Context Protocol (MCP) server for exploring Git commit history using semantic search. With this tool you can search through commits with natural language commands like “Search Git history to find out why this class was added”, or “search_commits(query=”authentication login changes”, limit=5)”. Uses Microsoft’s all-MiniLM-L6-v2 embedding model via sentence-transformers, or deterministic hash-based embeddings when sentence-transformers is unavailable. Written in Python (with a few Bash scripts), under MIT License.
- See also Spelungit: When git log --grep isn’t enough by Phil Haack on You’ve Been Haacked blog.
forgit is a utility tool powered by fzf (command-line fuzzy finder) for using Git interactively. Written in shell, under MIT license.
gitnr is a cross-platform CLI utility to create .gitignore files using one or more templates from TopTal (https://gitignore.io), GitHub, or your own collection. Written in Rust, under MIT License.
mani is a CLI tool that helps you manage multiple repositories. It’s useful when you are working with microservices, multi-project systems, multiple libraries, or just a collection of repositories, and want a central place for pulling all repositories and running commands across them. Written in Go, under MIT License.
eget is a command-line tool for easily fetching and extracting pre-built binaries from GitHub releases. Written in Go, under MIT License.
dunk is a tool to provide prettier Git diffs in the terminal by piping git diff output into it (git diff | dunk or git diff | dunk | less -R). In very early stages of development. Written in Python, under MIT License.
- See also git-delta, a syntax-highlighting pager for git, diff, grep, and git blame output. It was first mentioned in Git Rev News Edition #86, though there is another delta command-line diff tool which was first mentioned in edition #9.
- See also diff-so-fancy tool, which beside piping git diff output to it, can also be used as core.pager and interactive.diffFilter. It was first mentioned in Git Rev News Edition #13.
- There is also a contrib/diff-highlight diff pager script in the Git repository, written in Perl. It was mentioned in Git Rev News Edition #53.
GitType is a CLI tool that turns your own source code into typing challenges. Because why practice with boring lorem ipsum when you can type your beautiful fn main() implementations? Written in Rust, under MIT License.
Serie is a TUI tool that provides a rich Git commit graph in your terminal. Written in Rust, under MIT License.
- See also tig, an ncurses-based text-mode interface for Git, first mentioned in Git Rev News Edition #18.
prettydiff is a beautifier and language aware code comparison tool for many languages. It also minifies and does a few other things. There is a web service showing how the tool works at https://prettydiff.com/tool.xhtml. Written in TypeScript and HTML, under CC0 license.
fnox: Fort Knox for your secrets is a tool to manage secrets with encryption, or cloud providers, or both. Fnox uses a simple TOML config file (fnox.toml) that you check into Git; secrets are either encrypted inline, or provided as references that point to a secret in age, AWS, 1Password, etc. Written in Rust, under MIT License.
asdf is a tool version manager. All tool version definitions are contained within one file (.tool-versions) which you can check in to your project’s Git repository to share with your team, ensuring everyone is using the exact same versions of tools. Written mainly in Bash and Go, under MIT License.
grebedoc.dev is a service that offers static site hosting for Git forges; it publishes the pages branch in your Git repository as a website on your domain. More specifically, it is a public deployment of git-pages and Caddy, configured to work especially with Codeberg but also with other Git forges. It is operated by Catherine ‘whitequark’ and teammates.
- Compare with GitHub Pages, GitLab Pages, static websites on Bitbucket Cloud, Codeberg Pages (can’t guarantee high availability), sourcehut pages, and Cloudflare Pages (JAMstack platform), etc.
gitsuggest is a tool to suggest GitHub repositories based on the repositories you have shown interest in by “starring”. It is using the Latent Dirichlet Allocation (LDA) method. There is also a gitSuggest service (in beta) on Heroku. Written on Python, under MIT License.
Josh (Just One Single History) (repo) is a tool that combines the advantages of monorepos with those of multirepos by leveraging a blazingly fast, incremental, and reversible implementation of Git history filtering. Note that to guarantee filters are reversible Josh restricts the kind of filter that can be used. Use cases include partial cloning, workspaces, simplified CI/CD; this tool also provides a GraphQL API. Josh is distributed via Docker Hub, and you can start it with the appropriate docker run command. See its Frequently Asked Questions for comparison with git sparse-checkout, partial clone, submodules, git subtree, and git filter-repo. Written mainly in Rust, under MIT License.
Furgit (GitHub mirror) is a fast Git library in pure Go (and a little bit of optional Go Assembly). Written for Lindenii Villosa (successor to Lindenii Forge), a software forge primarily designed for self-hosting by small organizations and individuals. Under AGPL 3.0 license.
git-embigenner is a very simple shell script to cheat a high score on GitHub, which will spam commits to populate your profile’s contribution graph.
- Compare with Git Draw, a Chrome extension which will allow you to freely draw on your GitHub heatmap, mentioned in Git Rev News Edition #12
  and gitfiti, a tool for crafting graffiti in a GitHub commit history calendar, mentioned in Git Rev News Edition #41.
- Contrast Vigilante Justice on GitHub: GitHub Graffiti by Dylan Ayrey, mentioned in Git Rev News Edition #118, about how you can paint funny pixel art (graffiti) with fake commit Git histories on spammer/phisher’s GitHub profiles (that is, on their activity heatmap plot).

Releases

Git 2.52.0, 2.52.0-rc2, 2.52.0-rc1, 2.52.0-rc0
Git for Windows v2.52.0(1), v2.52.0-rc2(1), v2.52.0-rc1(1), v2.52.0-rc0(1)
GitLab 18.6.1, 18.5.3, 18.4.5, 18.6, 18.5.2, 18.4.4, 18.3.6
Bitbucket Data Center 10.1
Gerrit Code Review 3.10.9, 3.11.6, 3.11.7, 3.12.3, 3.13.0-rc5, 3.13.0, 3.13.1
GitHub Enterprise 3.18.1, 3.17.7, 3.16.10, 3.15.14, 3.14.19
GitKraken 11.6.0
GitHub Desktop 3.5.4
Git Cola 4.16.1
GitButler 0.18.1, 0.18.0
Kinetic Merge 1.11.2, 1.11.1, 1.11.0
Tower for Mac 15 (YouTube tour)
Tower for Windows 10

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Ayush Chandekar, Štěpán Němec, Bruno Brito and D. Ben Knoble.

Git Rev News Edition 128 (October 31st, 2025)

chriscool — Fri, 31 Oct 2025 11:06:51 +0000

Git Rev News: Edition 128 (October 31st, 2025)

Welcome to the 128th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of September and October 2025.

Discussions

General

Git participated in GSoC (Google Summer of Code) 2025

All the contributors have successfully passed their final evaluation and published a final report:
- Lucas Oshiro worked on the Machine-Readable Repository Information Query Tool project. He was mentored by Patrick Steinhardt and Karthik Nayak. The final report can be found on his website.
- Meet Soni worked on the Consolidate ref-related functionality into git-refs project. He was mentored by Patrick Steinhardt and Jialuo She. The final report can be found on his website.
- Ayush Chandekar worked on the Refactoring in order to reduce Git’s global state project. He was mentored by Christian Couder and Ghanshyam Thakkar. The final report can be found on his website.
Kaartic Sivaraam and Christian Couder were “org admins”.

Congratulations to the contributors, their mentors and the org admins!
Git Merge 2025 conference and Contributor’s Summit 2025

The Git Merge conference happened on September 29th and 30th in San Francisco, hosted by GitHub at their GitHub HQ. The session records are available.

On the second day, there was also the Contributor’s Summit. The full notes as well as notes broken down by topic are available.
Git Mini Summit 2025

On August 28 in Amsterdam, a Git Mini Summit happened as a co-hosted event of the Open Source Summit Europe, sponsored by GerritForge, GitButler, GitLab, and Google. The schedule and session records are available.

Support

[Change] Git build issue on NonStop

Randall S. Becker reported on the mailing list that CI tests on the NonStop x86 platform were broken after the uintptr_t type started to be used in clar tests when displaying error messages in test failures (in case pointer comparisons fail).

Jeff King, alias Peff, replied to Randall that uintptr_t was already used in many places in the regular code, and guessed the issue might come from how clar defined that type. He noted though that the line in the clar test where uintptr_t appeared also contained PRIxPTR which is a macro that is not used in the regular code. So he wondered if just replacing that macro with PRIuMAX (which is often used) would be enough to fix the issue.

PRIxPTR, PRIuMAX and similar macros are format specifier macros from the C standard library (defined in <inttypes.h>) that provide portable ways to print integer types using functions like printf() across different platforms. They are all named in the same way, with PRI meaning printf, the next letter indicating the format, like x for hexadecimal and u for unsigned decimal, and the last part indicating the type, like PTR for pointer-sized integers, MAX for maximum-width integers, 64 for 64-bit, etc.

Randall replied to Peff that replacing PRIxPTR with PRIuMAX would work, and that he was going to try it.

Patrick Steinhardt also replied to Randall and Peff saying it would work, and asked Peff if he wanted to send that change.

Peff replied to Patrick that he’d be happy if Patrick sent the change, but noted that using PRIxMAX might be better than PRIuMAX as the code wanted to print hexadecimal values.

Patrick then reported to Peff that Peff’s suggestion to use the PRIxMAX or PRIuMAX format specifier macros didn’t work on 32 bit systems, because casting a pointer to an integer of different size (the pointer is 32 bits, but uintmax_t is 64 bits) fails.

Patrick proposed using %p as a format specifier saying it might be a better trade-off. The downside was that the output format would be unpredictable across platforms as %p doesn’t have a standardized output format. So tests that validated the exact error message format would have to be dropped. But at least %p would work everywhere and produce stable output.

Junio Hamano, the Git maintainer, agreed with Patrick that %p was “the most appropriate solution”.

Randall then confirmed that %p worked on NonStop x86 even if the man pages warned to the contrary.

The %p solution was eventually merged to the ‘master’ branch.

Developer Spotlight: Kristoffer Haugsbakk

Who are you and what do you do?

I’m Kristoffer from Norway. My day job is working on a Java webapp primarily used for clinical mental health questionnaires.
What would you name your most important contribution to Git?

One I like was when I and the mailing list collaborators fixed a bug related to Git notes handling by git-format-patch(1). It’s small and niche but Git notes handling is very important to me; I think Notes are a great way to maintain metadata between patch submissions. In fact I think it’s great for most commit metadata that I am interested in maintaining.

What are you doing on the Git project these days, and why?

The one I am focusing on is improving the git-patch-id(1) documentation. It so happens that you can use that command to make a commit—patch-id mapping for the whole repository, which you then in turn can use to make an improved git-cherry(1) oneliner (one that says what the upstream commit hash is) as well as, say, using commands like git-range-diff to see if the upstream committer made any changes to your submission like fixing commit message typos. But most uses of this command that I see just use it to figure out what the patch ID of one single commit is and have to script everything around that, like loop over git-rev-list(1).

If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I would ask them to find a way for projects to define their own conventions and preferences that can be easily shared with all contributors. Something better than asking each contributor to download and install hooks. Projects need a better and more declarative way to configure how their project is supposed to work. One example might be that a project does not want merge commits to land in the mainline. It should be simple to take that high-level goal and make sure that the in-effect central repository never gets any merge commits.

Git will not be replaced any time soon, despite it being more difficult to use than it ought to be. But we can already see what the effects of the high difficulty of using it is: some projects outsource all commit messages to issue trackers, and change proposals (pull requests and patch series descriptions) to webapp forges. (Meaning they don’t even duplicate the PR description somewhere in Git like in a commit message.) What you end up with is still Git but with all the interesting information living at least one hyperlink away.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I can’t think of a single thing to remove that would have a big impact.

I guess I would remove git-filter-branch(1). People can use git-filter-repo(1). And with that one removed I wouldn’t have to ask people to not use it any more. ;)

Documentation contributions require understanding both the technical implementation and the user perspective. How do you approach bridging that gap? Do you have strategies for ensuring documentation stays accurate as code evolves?

Most of the challenge in bridging the gap for me is about trying to describe things accurately while not being tedious and verbose. The worst challenge is when I realistically have one paragraph to explain something but there are eight factors to mention. (Not a real case; just the feeling of a challenge that I have encountered before.)

For things that are either just difficult or have many factors to consider I think the best approach we have right now is to mention other documentation pages in parentheses. An obvious candidate is gitglossary(7) where we can gather all kinds of jargon and be as verbose as we want to. :)

I don’t have any strategies for ensuring that documentation stays accurate as code evolves. Let’s take something concrete as an example: an update to the documentation adds a very similar paragraph to two documentation pages. That is an obvious maintenance burden since a later update is likely to necessitate a change in both places, but you are likely to only deal with one of them. The obvious fix is to parameterize the paragraph. But I don’t have good indirect experience with that in AsciiDoc; the last time I saw something parameterized was when an AsciiDoc macro forced inline formatting to be handled literally. The cure seems worse than the disease to me.

The best I can do now when making updates is to investigate the lines that I am changing and find the histories of any possible near-duplicate texts.

What is your favorite Git-related tool/library, outside of Git itself?

Magit. An Emacs Git frontend.

Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

When I added a test case to t/t7001-mv.sh that made the continuous build routine on Windows (CI) time out. The test was test_expect_failure and triggered a C assertion, and the Windows CI pops up a modal dialog on assertion failures. That dialog is of course never dismissed by any operator and so the suite eventually timed out.

What is your toolbox for interacting with the mailing list and for development of Git?

I use the builtin commands for making patches and sending them (git-format-patch(1) and git-send-email(1)). For programming and writing I use the basic, needed tools along with Emacs. Very occasionally I will use GDB.

What is your advice for people who want to start Git development? Where and how should they start?

Find something technically wrong in the documentation and fix it. That’s what I did in 2016; I wanted to test out this new (to me) “email-based workflow”. Focus on fixing things instead of subjectively improving something. Because someone might object and propose that you send a new version. Making subjective documentation improvements is the next step in terms of difficulty I guess.

It sounds trivial but someone used to Git forges will have enough challenges just sending proper patches to the project over email.

Also read through Documentation/SubmittingPatches. I don’t really see many corrections that refer to other documents. You could of course get a correction that refers to some lore but that is unlikely to happen for simple changes if you just structure it similar to recent, accepted submissions that you find.

If there’s one tip you would like to share with other Git developers, what would it be?

You won’t get any C programming tips from me since I can’t write or edit three lines of C code without segfaulting five times.

Take advantage of the fact that the Git history is so well-structured. Maybe you find some questionable behavior or code. Use the “pickaxe” technique (see git-log(1)) on some good candidate text and trace the behavior back to the start. Maybe the commit message explains the issue or behavior. If not use refs/notes/amlog (which you should be “subscribed” to already) and see if something relevant was discussed on the patch discussion. If not there is likely to be no written record out there; another thing that this project is disciplined about is keeping the relevant discussion on the mailing list, not the mailing list and N other satellite fora.

Those links (to commits and archived emails) are very valuable when you want to discuss a change to something that has been in git(1) for years and years.

Other News

Various

Git considers SHA-256, Rust, LLMs, and more by Jonathan Corbet on LWN.net.
Git Developers Talk About Potentially Releasing Git 3.0 By The End Of Next Year by Michael Larabel on Phoronix.
GitHub is migrating to Azure! And goodbye to new development for a year. by Redazione RHC on Red Hot Cyber.
Fedora Moves Towards Forgejo by Matthew Miller and Akashdeep Dhar on December 4, 2024 in Fedora Magazine.
- Forgejo is a self-hosted lightweight software forge, written in Go; nowadays a hard fork of Gitea (which in turn was based on Gogs). It was first mentioned in passing in Git Rev News Edition #103.

Light reading

Building for the future: on Tangled’s existence and direction by Anirudh Oppiliappan on their blog; also published at icy takes blog on ATProto.
- Tangled.sh is a new social-enabled Git collaboration platform built on top of the AT Protocol / ATProto (which is behind the BlueSky microblogging federated social media service). It was first mentioned in Git Rev News Edition #125.
6 months of Tangled: a quick recap, and notes on the future by Anirudh Oppiliappan and Akshay Oppiliappan on Tangled Blog.
Socially self-hosting source code with Tangled on Bluesky by Anil Madhavapeddy, Professor of Planetary Computing, on his blog.
Redistributing Git with Nostr by início on their blog.
- There exists gitstr (git str), which is a tool to send and receive Git patches over Nostr, using NIP-34 (first mentioned in Git Rev News Edition #109).
- Note that git-credential-oauth, a Git credential helper that securely authenticates to GitHub, GitLab, BitBucket and Gerrit using OAuth, can replace the “create an account; pick a password; confirm an email address; set up SSH keys for pushing” steps.
How GitHub won software development by Nick Hodges on Rubber Duck Reflections opinions blog on InfoWorld.
You already have a git server on Maurycy’s blog; describes how one can serve Git repositories via SSH (with SSH access) or via dumb HTTP (with a web server).
Simple automated deployments using git push by Gabriel Garrido on his blogs / notes (2024).
Discussion of the Benefits and Drawbacks of the Git Pre-Commit Hook by Hannes Leutloff on his blog.
You can use fzf to review git commits by Julia Evans in her TIL (Today I’ve Learned) section.
- See also Improving shell workflows with fzf, mentioned in Git Rev News Edition #74, and Curing A Case Of Git-UX, mentioned in Git Rev News Edition #126.
Switch to Jujutsu already: a tutorial by Stavros on Stavros’ Stuff.
- Jujutsu (jj) is a Git-compatible version control system written in Rust, which was first mentioned in Git Rev News Edition #85.
Magit Is Amazing! by Abdallah Maouche (heiwiper) on his blog (how it does things that others need to use Jujutsu over Git for).
- Magit is a popular Emacs editor interface to Git, first mentioned (in passing) in Git Rev News Edition #6.
Branching in a Sapling Monorepo
- Sapling is a scalable, user-friendly, and open-source source control system that powers Meta’s (Facebook’s) monorepo. It was first mentioned in Git Rev News Edition #93.
Stop Rebasing Everything: Your Git History Isn’t That Special, an argument in the merge-vs-rebase debate. by Guillaume on DEV.to.
Diff Algorithms by Florian Zenker on his website.
The result of this exploration was znkr.io/diff, a difference algorithm module for Go.
- Note that with git diff you can choose between myers (default), minimal, patience and histogram algorithms.
Git Super-Power: The Three-Way Merge by Quentin Santos on his blog (2024).
Provides the following tl;dr: git config --global merge.conflictstyle diff3.
Anyone Can Commit Code as You on GitHub (Here’s How to Stop Them) with signed commits (with tutorial focusing on macOS using GPG Keychain). Written by Nick Taylor on his Just Some Dev blog.
GitHub Ensloppification by David Bushell on his blog.
“GitHub” Is Starting to Feel Like Legacy Software rant by Misty De Méo on her blog (2024).
Implementing Conventional Commits with Jira Ticket Prefix Validation by Alexandre Mogère (heristop) on Zazen Code.
- The Conventional Commits specification was first mentioned in Git Rev News Edition #52, and in many editions since.
Conventional Commits considered harmful (or rather overly strict enforcement of the standard), rant by Salih Muhammed, with a few further links.
Contribute to GitFichas by Jessica Temporal on her blog.
- GitFichas (also know as GitStudyCards) is a collection of study cards about Git, for devs that might need a refresher about Git commands. Mentioned in the previous edition of Git Rev News.

Easy watching

Gerrit User Summit 2025, featuring also GitButler and Jujutsu by Luca Milanesio on GerritForge’s YouTube channel.
Jujutsu at Google (slides) on Google for Developers channel on YouTube; part of JJ Con 2025 playlist.
In this talk, Martin von Zweigbergk presents on Jujutsu architecture and future plans.
JJ Con 2025 was a dedicated conference hosted by Google for the Jujutsu version control system.
Solving Git’s Pain Points with Jujutsu (with Martin von Zweigbergk) on Developer Voices channel on YouTube.

Scientific papers

Ya-Nan Li, Yaqing Song, Qiang Tang, Moti Yung: “End-to-End Encrypted Git Services”, Cryptology {ePrint} Archive, Paper 2025/1208, https://eprint.iacr.org/2025/1208, DOI:10.1145/3719027.3744815
- See “Scientists develop end-to-end encryption for git services” article by University of Sydney, edited by Stephanie Baum, reviewed by Robert Egan, on TechXplore.
S.R.P. van Hal, M. Post, K. Wendel: “Generating Commit Messages from Git Diffs”, arXiv:1911.11690 (2019)
mentions “inherent shortcoming of current commit message generation models, which perform well by memorizing certain constructs.”

Git tools and sites

diff-modulo-base is a tool that allows you to compare the relevant changes of two versions of a rebased branch given three input diffs: two base diffs that show the changes since the respective merge bases and a target diff between the branches you are actually interested in.

It is very similar to (and actually builds on) git range-diff, but differs in resulting output. Written in Rust, under MIT License.
Worktree Manager (wtm) is a fast, modern CLI tool for managing Git worktrees in bare repositories. Written in TypeScript for Bun, under MIT License.
git-metrics is a Git extension that makes it possible to track metrics about your project, which are stored within the git repository (using git notes). Written in Rust, under MIT License.
Described in Build metrics and budgets with git-metrics article by Jérémie Drouet on DEV.to (2024).
- There is another git-metrics tool, by the Praqma / Eficode DevOps company, which consists of a set of scripts to analyse a Git repository for metrics such as lead time and open branches. Written in Python, no license provided. It was mentioned in passing in Git Rev News Edition #48.
git-spice is a tool for stacking Git branches. It lets you manage and navigate stacks of branches, conveniently modify and rebase them, and create GitHub Pull Requests or GitLab Merge Requests from them. Written in Go, under GPL 3.0 License.
- A stacked branch refers to a set of branches that build upon each other in a linear sequence. Stacked branches or stacked diffs were first mentioned in Git Rev News #44, and most recently in Git Rev News #127, where you can find even more links about this technique.
Git Granary is a Git Large File Storage (LFS) server implementation written in TypeScript. Under MIT License. Git Granary was designed for self-hosted personal use.
See Git Granary blog post by David Bushell on his blog (2024).
gibr is a Git CLI tool for intelligently creating branch names. It connects your Git workflow to your issue tracker for that purpose; currently supporting GitHub, GitLab, Jira, and Linear (with Monday.com support planned). Written in Python, under MIT License.
0github.com is a service offering a heatmap diff viewer for code reviews, color-coding every diff line/token by how much human attention it probably needs. To try it, replace github.com with 0github.com in any GitHub pull request URL. The cmux engine it uses is open source (MIT License). It uses a LLM (Large Language Model) to perform this task.

Releases

Git 2.51.2, 2.51.1
Git for Windows v2.51.2(1), v2.51.1(1), v2.51.0(2)
GitHub Enterprise 3.18.0
GitLab 18.5.1, 18.4.3, 18.3.5, 18.5, 18.4.2, 18.3.4, 18.2.8
Gerrit Code Review 3.10.9, 3.13.0-rc0, 3.13.0-rc1, 3.13.0-rc2, 3.13.0-rc3, 3.13.0-rc4, 3.13.0-rc5
GitKraken 11.5.1, 11.5.0
GitHub Desktop 3.5.3
Git Cola 4.16.0
GitButler 0.16.10, 0.16.9
Kinetic Merge 1.10.0, 1.9.1

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Kristoffer Haugsbakk, Lee Reilly, Luca Milanesio and Štěpán Němec.

Git Rev News Edition 127 (September 30th, 2025)

chriscool — Tue, 30 Sep 2025 11:06:51 +0000

Git Rev News: Edition 127 (September 30th, 2025)

Welcome to the 127th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of August and September 2025.

Discussions

Support

Doing blobless clone by default; switching between blobless, treeless and full clones by a command

Dilyan Palauzov (Дилян Палаузов) sent an email to the Git mailing list where he proposed making blobless cloning (--filter=blob:none) the default behavior for git clone via a global configuration option. He also suggested adding a command to download all locally missing history, a command to convert a repository to a pure treeless or pure blobless clone, and a config option to make blobless clone the default behavior when running just git clone <URL>.

He said that most users used git clone to build or change software, not to immediately analyze history with commands like git log. Therefore, a reduced data download would speed up initialization, save bandwidth, and reduce server load.

Kristoffer Haugsbakk replied saying the proposed command to “download all locally missing history” for treeless and blobless clones “sounds like git-backfill(1)”. He also noted that he had “never used blob/treeless” clones himself.

Derrick Stolee, who likes to be called just “Stolee”, and who contributed the git backfill command, replied to Kristoffer confirming that git backfill is intended to assist with downloading the missing blobs in a blobless partial clone.

About treeless clones though, he noted that git backfill is not optimized for them, and that treeless clones are generally not intended for “refilling,” as downloading missing trees is “particularly expensive”.

Stolee suggested using scalar clone, which is already shipped with Git, instead of making blobless cloning the default, as scalar clone was contributed partly to allow users to opt into a version of git clone that incorporates “best practices and advanced features as they are developed”, while git clone maintains backward compatibility. He recognized that scalar clone might not be “discoverable enough” though.

Junio Hamano replied to Stolee’s suggestion that a future command like git big-clone could emerge from the feedback on scalar clone. He said a separate command like git big-clone would not be discoverable enough either. Instead as a new feature matures, it should be a welcome change for git clone to borrow it as a new option. Such optimizations (like those for large repos) could be automatically enabled based on the repository’s size, provided it was done with end-user consent.

Patrick Steinhardt replied to Stolee about treeless clones. He agreed that the existing command git backfill is not optimized for refilling treeless clones, and proposed an idea to backfill trees by batching based on depth, but concluded that this method was “definitely not ideal” and would perform “way worse compared to backfilling blobs”.

Patrick also said that for these reasons he generally recommends not to use treeless clones at all.

Stolee replied to Patrick agreeing with the general caution regarding treeless clones, and that they were “not a good approach for doing ongoing work as a human”.

However he noted that they are useful if a user needs the speed of a shallow clone combined with the ability to analyze commit history (though with no path history) for an “ephemeral scenario like a CI build”. But they are a “tool for a very narrow case” and should only be used by those who understand how to avoid their pitfalls. Patrick then agreed with that point of view.

Konstantin Ryabitsev, the system administrator for kernel.org, replied to the original email from Dilyan about making blobless clones the default behavior for git clone. He said a counter-rationale to this proposal was that shallow clones (which include blobless clones) generate significantly more load on the server side.

The reason is that for these partial clones, no pre-existing packs are available for the operation, requiring more computation from the server. So changing the default behavior for git clone could likely result in slower clones for everyone and lead to more unavailable servers due to the high load.

Ben Knoble also replied to Dilyan’s original email by opposing the proposal to make blobless clones the default behavior while agreeing that managing this preference via a config option was a reasonable compromise.

Ben’s opinion was that such a default behavior would defeat the “tremendous advantage of distributed version control”, which is about having the whole repository available independently. It would also make some of his use cases more difficult as he frequently clones repositories specifically to run “history spelunking searches”.

He noted that he primarily deals with repositories where the issue isn’t about clones, but about mismanaging large binary files in history, which causes large blobs and clone times.

Developer Spotlight: Toon Claes

Who are you and what do you do?

I’m Toon from Belgium. My name is pronounced like “tone” (rhymes with “bone”), and not like the “toon” in “cartoon”, but usually I’m already happy if people remember my name 😉.

I’m employed by GitLab for more than 8 years, and since late 2024 I’ve been part of the Git team, contributing to the Git project. I’ve started my professional career in 2008 building software for a payment terminal running embedded GNU/Linux using C & C++. Later I’ve transitioned into doing web and mobile development for a while. And now recently, I’ve been circling back to more lower-level programming, contributing to Git using C.
What would you name your most important contribution to Git?

I’m fairly new in the Git community, but recently I’ve been working on adding git last-modified(1). It’s a sub-command that will be released in Git v2.52. This command finds the commit that last modified each path in a tree. It can be used on forges (like GitLab, GitHub, Codeberg), to show commit data in a tree view.
What are you doing on the Git project these days, and why?

The subcommand git last-modified(1) was recently merged in the ‘master’. But there’s more work to be done to improve its performance.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Once data is committed to Git, and it’s made part of the history (i.e. committed or merged into the default branch), it’s trapped forever. This is a core principle of Git: you cannot rewrite history without changing commit hashes. This is very powerful, but also problematic in some scenarios.

For example, at my $DAYJOB we receive commonly the request from customers to remove confidential or sensitive information from a Git repository. This is not possible without rewriting history. Or when, by accident, large files are committed to Git, you cannot get them out (without rewriting history). Or people might want to remove/change their personal information in a repository, for example when they transition genders.

Can we (and should we?) build something that removes and overwrites pieces of history, without changing commit hashes? It’s a slippery slope, because from experience I know Git users are very creative and might use this feature in ways it was not intended for.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The use of the double .. and triple ... dot notation in gitrevisions(7) and git diff(1). I even once ranted about it in a video.
What is your favorite Git-related tool/library, outside of Git itself?

I’m a big fan of Magit. It’s arguably the best tool to interact with Git and I also learned a lot from it. I consider myself an advanced Git user, but I wouldn’t be able to split up changes in several commits without Magit.

Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

One of my earliest contributions to Git was a bug fix in the code used by git bundle create. We noticed sometimes references didn’t end up in the bundle. After a lot of digging I submitted a patch that removed about 30 lines of code written way back in 2007. The code from 2007 caused references to be skipped if they were modified while the git bundle create process was running. But it wasn’t needed anymore due some changes made in 2013, although no one ever realized that. You can read more about it in the patch.

It was really satisfying to submit a patch that was nothing more than code deletion of really old code (and adding some tests). And it taught me to write a good commit message, which I was praised for by the maintainer. It was a very nice experience as a newcomer in the community.

What is your toolbox for interacting with the mailing list and for development of Git?

I mostly live in Emacs and my terminal (zsh). I consume email in Emacs using notmuch. To submit patches I use b4, which I also sometimes use to pull in patches. But I also sometimes pull in the branches from Junio’s fork or the fork shared across my colleagues.

In Git, I compile and unit test changes using Meson. Its use was introduced in the Git project around the end of 2024. It’s reliable because it prevents me from forgetting to recompile before running tests; it’s fast because it parallelizes compilation by default and automatically uses Ccache; it allows out-of-tree builds, which is really convenient if you want to benchmark various revisions of Git.

What is your advice for people who want to start Git development? Where and how should they start?

Learn to navigate the mailing list archive. It lacks structure so things can be hard to find, but there’s so much information up there. If you’re interested in a topic, or you think you’ve found the bug, start digging. Use git blame(1) to find the commit that introduced the changes and look up the conversation around it in the mailing list archive. This will help you understand why some decisions are made. Also it familiarizes you with the people in the community, how they think, how they communicate, and what’s expected from you. Having the knowledge from those conversations can help you build a strong case whenever you’re submitting a feature change or bug fix.

Other News

Various

What’s next for Git? 20 years in, the community is still pushing forward by Lee Reilly on GitHub Blog - mainly about the Git Merge 2025 talks lineup.
Git Developers Debate Making Rust Mandatory by Michael Larabel on Phoronix.
A policy for Link: tags (for Linux), by Jonathan Corbet on LWN.net.
Working almost continuously for six months, Yasin Dehfuli completed the Persian translation of the ProGit book.
An initiative to refresh the look and content of https://git-scm.com/ has been kicked off by Toon Claes. Contributions welcome, especially from visual designers!

Light reading

git-flow-next: The Next Iteration of Advanced Git Workflows by Bruno Brito on Tower Blog.
A kludgy new way to git-blame by D. Ben Knoble on his Junk Drawer personal blog, about the new git-greb script that feeds git grep to git blame (with appropriate options) in order to blame matching lines.
My new git utility what-changed-twice needs a new name by Mark Dominus (陶敏修) on his The Universe of Discourse blog, about the tool to help get related changes into the same commit.
Supercharge your Git workflows by Darwin Sanoy on GitLab Blog, about how to optimize git clone operations in any environment, reducing clone time and disk space, with the Git Much Faster script.
- Compare with Scalar, a tool that helps Git scale to handle large Git repositories by enabling some advanced Git features. Scalar was first mentioned in Git Rev News Edition #60, and now is part of Git: scalar - A tool for managing large Git repositories. The Story of Scalar was mentioned in Edition #92.
The Origin Story of Merge Queues by Julien Danjou on Mergify Blog. This article traces merge queues history (from Bors and Homu to Bulldozer, Kodiak, Mergify, GitHub and GitLab), why they emerged, and how they became a standard in modern software development.
- Mergify.com, a web service for automating pull requests (free for open-source projects), was mentioned in Git Rev News Edition #87.
Git - Fun Facts by Rubansi Vincent on DEV.to: a mix of fun and surprising facts about Git.
diff –stat for binary files (in the Jujutsu version control system) by Evan Martin on neugierig.org: Tech Notes.
- Jujutsu (jj) is a Git-compatible version control system written in Rust, first mentioned in Git Rev News Edition #85.
Jujutsu For Busy Devs, Part 2: “How Do I…?” by Madeleine Mortensen, continues the Jujutsu For Busy Devs series, mentioned in Git Rev News Edition #125.
Dear GitHub: no YAML anchors, please by William Woodruff (yossarian) on his ENOSUCHBLOG blog. He says that they are redundant with existing functionality, make CI/CD human and machine comprehension harder, and their support in GitHub Actions does not introduce any new, previously unavailable features.
Custom VC-Focused Emacs Functions I Created to Enhance My Git Workflow by Rahul M. Juliato on Rahul’s Blog.
How to delete all squash-merged local git branches with one terminal command (which you probably shouldn’t use), by Salma Alam-Naylor on her blog.
finding deleted content using git logs by Sindre Kjelsrud, also known as “Sid”, on Sids’ blog: a short note on git log -S.
Git exclude, a handy feature you might not know about by Marijke Luttekes on her blog, about .git/info/exclude.
Git Dual Remotes: a short note by Mark H. Nichols on his Zanshin.net personal site, about the difference between git push and git fetch with multiple URLs, and jj git push --all-remotes.
Migrating from Gitea to Forgejo the long way by Harsh Shandilya on his blog.
Gitea and Forgejo are software forges.
Some thoughts on personal git hosting by Terence Eden on Terence Eden’s Blog.
Setting up cgit with Caddy v2 web server by Simon Garrelou on his SixFoisNeuf blog (2022).
Sourcegraph went dark by Eric Fritz on his blog (2024), about the work that went into ensuring that references are kept alive after the sourcegraph/sourcegraph repository went private (there is a public snapshot available at sourcegraph/sourcegraph-public-snapshot, which is a read-only archived repository).
How to use stacked PRs to unblock your entire team by Ninad Pathak on Graphite Blog (2024), and
A guide to using Graphite’s stacked PRs for GitHub users by Martin Jambon for Semgrep on DEV.to.
- See also Stacked Branches with GitButler by Scott Chacon on the GitButler Blog, mentioned in Git Rev News Edition #118.
- See also Understanding the Stacked Pull Requests Workflow by Bruno Brito on Tower’s blog, mentioned in Git Rev News Edition #111 together with various other articles and tools about stacked diffs, stacked PRs, and stacked branches.
- See also Rethinking code reviews with stacked PRs by Ankit Jain on the Aviator blog, mentioned in Git Rev News Edition #115 with links to more sites and tools related to stacked PRs, etc.
GitButler’s new patch based Code Review (Beta) by Scott Chacon on GitButler’s Blog.
first-class merges and cover letters by Tony Finch on his blog.

Slightly heavier reading

Quo Vadis, Code Review? Exploring the Future of Code Review, a scientific article from August 2025, arXiv:2508.06879 (most authors of the paper are from Blekinge Institute of Technology, Karlskrona, Sweden).
Code Review as Decision-Making – Building a Cognitive Model from the Questions Asked During Code Review, a scientific article from July 2025, arXiv:2507.09637 (all authors are from Lund University, Lund, Sweden). Submitted to Empirical Software Engineering, Springer Nature.

Easy watching

Git Mini Summit 2025 Videos by Scott Chacon on GitButler’s Blog.
Kinetic Merge in action
12 Git commands visualized in 3D: a spatial approach to understanding version control [4:58], on the Initial Commit channel on YouTube.
Stacked Branches With Lazygit [12:18] by Jesse Duffield (Lazygit author) on YouTube.
- lazygit is a simple [windowed] terminal UI for Git, written in Go. It was first mentioned in Git Rev News Edition #42.

Git tools and sites

Kinetic Merge is a command-line tool that helps you merge a heavily refactored codebase and stay sane. Its goals are to:
- Merge two branches of a Git repository holistically across the entire codebase.
- Take into account the motion of code in either branch due to refactoring.
- Handle file renames, file splits, file concatenation.
- Handle code being excised from one place in a file and moved elsewhere in that file or to somewhere within another file, or hived off all by itself in its own new file.
- Work alongside the usual Git workflows, allowing ordinary Git merge to take over at the end if necessary.
- Be a simple command line tool that tries to do as much as it can without supervision, and with minimal supervision when complexities are encountered.
Written in Scala, under an MIT license.
Git Much Faster is a comprehensive benchmarking tool for comparing different Git clone strategies, especially for large repositories. Written as a Bash shell script, under MIT license.
prek is a reimagined version of pre-commit, built in Rust. It is a framework to run hooks written in many languages, and it manages the language toolchain and dependencies for running the hooks. prek is not production-ready yet: some subcommands and languages are not implemented. Under MIT license.
- See also Ready prek go! article by Hugo van Kemenade on his blog.
git-sqlite is a collection of shell scripts, including a custom diff and merge driver for SQLite, that allows a SQLite database to be tracked using the Git version control system. Under MIT license.
LearnGit.io teaches version control using animated visualizations of Git internals—and is now free for students and teachers. Created by Jack Lot of The Modern Coder YouTube channel, LearnGit offers 41 video lessons across 11 modules, along with quizzes, a Git command search, and high-quality written documentation. Educators can email jack@learngit.io for bulk vouchers. First mentioned in Git Rev News Edition #108.
GitFichas (also know as GitStudyCards) is a collection of study cards about Git, for devs that might need a refresher about Git commands. GitFichas is now open-source and undergoing some construction.
Git’s home page now has a Learn section, including a handy Git Cheat Sheet, contributed by the ever-industrious Julia Evans. These contributions are part of the initiative to refresh the look and contents of git-scm.com.

Releases

Git for Windows v2.51.0(2)
Gerrit Code Review 3.13.0-rc0
Bitbucket Data Center 10.0
GitHub Enterprise 3.17.6, 3.16.9, 3.15.13, 3.14.18
GitLab 18.4.1, 18.3.3, 18.2.7, 18.4, 18.3.2, 18.2.6, 18.1.6
GitKraken 11.4.0
Sourcetree 4.2.14
tig 2.6.0
Garden 2.3.0
Git Cola 4.15.0
GitButler 0.16.8, 0.16.7
Kinetic Merge 1.9.0
git-credential-oauth 0.16.0
Tower for Mac 14.4, 14.5
git-flow-next 0.1

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Toon Claes, Johannes Schindelin, Bruno Brito, Gerard Murphy, Jack Lot, Ben Knoble and Štěpán Němec.

Git Rev News Edition 126 (August 31st, 2025)

chriscool — Sun, 31 Aug 2025 11:06:51 +0000

Git Rev News: Edition 126 (August 31st, 2025)

Welcome to the 126th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of July and August 2025.

Discussions

Support

[BUG] git pull ignores pull.autostash=true configuration when used with --git-dir and --work-tree flags on a bare repository

Bryan Lee posted a bug report about the pull.autostash configuration variable being ignored in a repository used to manage his dotfiles.

He expected his unstaged changes to be automatically stashed before a pull when that configuration variable is set to true. Instead, the command failed with an error message telling him to “Please commit or stash them”. So he thought Git ignored the autostash configuration completely due to the setup, which consisted of a bare repository and a separate work tree accessed through the following alias:

$ alias dot='git --git-dir=$HOME/.dotfiles/ --work-tree=$HOME'

Lidong Yan replied to Bryan admitting that he wasn’t sure why the autostash feature would be ignored when using the --git-dir and --work-tree flags. He suggested setting rebase.autostash instead of pull.autostash to true though.

Bryan Lee thanked Lidong saying that pull.autostash was not a Git configuration option and that rebase.autostash did work for rebase operations. But he raised the issue that Git silently accepts invalid configuration keys without any warning, which can cause users to waste a lot of time debugging.

Lidong replied with a suggestion to add a git config verify subcommand. But Junio Hamano, the Git maintainer, chimed in expressing doubts about such a command, as Git cannot distinguish between a typo of a known variable and a legitimate custom variable that a user or a third-party tool might be using. Lidong elaborated that such a command could work by having Git maintain an internal registry of all valid keys, which could also be extended by users and tools for their own custom configurations.

Johannes Sixt suggested that instead of building a complex verification system, it would be easier to fix the origin of the misconception that pull.autostash was the correct configuration.

Junio replied to Johannes that having git pull pay attention to rebase.autostash was at least a documentation failure, if not a bug. He argued that users have different expectations for a relatively safe local rebase compared to a pull from a remote, which could be riskier. Also it didn’t make sense for git pull to respect rebase.autostash but not merge.autostash.

Ben Knoble then chimed in with a counter-argument to Junio. He reasoned that since a git pull that rebases is conceptually a fetch followed by a rebase, it would be “far more inconsistent” if it didn’t honor the rebase configuration. Breaking that expectation would be unnatural for users taught to think of pull in that way. Following this logic, he also supported the idea that a merging pull should respect merge.autostash.

Then Junio wondered if introducing a new, dedicated pull.autostash variable would be a good idea. But soon Lidong came up with a patch to actually add this configuration variable.

Eric Sunshine reviewed the patch and left a number of suggestions to improve it in many ways. After some discussions with Lidong and Junio, Lidong posted a version 2 of the patch.

This new version implemented a number of improvements based on the discussion. Some tests were added. The logic was updated to fall back to either rebase.autostash or merge.autostash depending on whether the pull performed a rebase or a merge. The order of precedence was also clarified: pull.autostash now overrides the more general rebase.autostash and merge.autostash settings. Finally, the documentation was updated with more precise explanations.

This feature was released recently as part of Git v2.51.0.

Developer Spotlight: Seyi Kuforiji

Who are you and what do you do?

My name is Seyi Kuforiji, and I’m an Outreachy alum who worked on modernizing Git’s unit testing platform by converting its homegrown unit test framework to use Clar. I studied geography at the University of Lagos, but my curiosity and passion for computers and software drove me to start learning Python and Git immediately after graduating.

Since then, I’ve enjoyed exploring different areas of IT, from software engineering to data science and DevOps, because I genuinely love learning and experimenting with new tools. I also earned a certification in Health Data Science and Precision Medicine from Stanford University, which reflects my commitment to leveraging technology to improve lives. Participating in Outreachy through Git demonstrated to me the impact of open-source collaboration, and it has strengthened my passion for developing solutions that give back to the community.

Outside of work, I’m usually diving into something new. Right now, the Linux graphics stack has caught my attention, but when I decide to give my brain a break from tech, I play chess or watch sports.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your Outreachy project?

Git was one of the first tools I ever learned years ago. At first, I didn’t really understand it; I only knew a few commands like git clone, git add ., and git commit -m "<message>", and I was living life with just those. I remember during my 12-month software engineering bootcamp, I helped some of my colleagues with Git because I had this so-called “prior knowledge”, and for a while, I was treated like a genius, at least until they caught up!

So when I saw Git on the list of Outreachy projects, I knew right away that this was where I needed to be: to deepen my understanding of the tool and maybe level up from “genius” to something closer to expert wizardry. These days, some say I’m a wizard, others say I’m a maestro, but I’m just a humble guy who enjoys learning and sharing knowledge.
How do you feel your contribution has impacted the Git community or the broader open source ecosystem?

My contribution to Git, which was modernizing its homegrown unit testing framework to use Clar, has helped improve Git’s testing capabilities by making the tests more maintainable, easier to understand, and easier to extend to cover more edge cases in the future. Clar brings additional benefits such as clearer test reporting, a more structured way to organize tests, and improved readability, which makes the testing process more approachable for new contributors. While this was primarily an internal-facing improvement, I believe it plays an important role in maintaining the reliability of Git’s functions and operations. A stronger testing framework makes it easier for both new and experienced contributors to work with the codebase confidently, which in turn strengthens Git for the millions of people who rely on it every day.
Is there any aspect of Git that you now see differently after having contributed to it?

Like I said earlier, I started out only knowing a handful of Git commands to do basic operations. My biggest takeaway since contributing to Git has been discovering the full power of its interactive rebase. I always saw rebase on cheat sheets but never really experienced its capabilities until I worked more deeply with Git. The best way I can describe it is that it feels like a time machine: I make changes and commits, Git captures those states in time, and with interactive rebase, I can go back, rewrite history, and improve it as if it were the first time.

I still find it so cool that in my text editor, I can see files I had already deleted in later commits come back to life during a rebase. It completely changed how I view Git, not just as a version control system, but as a powerful storytelling tool for code.
How do you balance your contributions with other responsibilities like work or school?

I usually create a schedule with a clear timeframe dedicated to working on the Git project. For example, during Outreachy, I set aside specific blocks of time each day, treating it almost like a regular job. This helped me stay consistent, avoid distractions, and make steady progress.

I’ve learned that balancing open-source contributions with other responsibilities is all about structure and prioritization. By planning my week ahead, I can make sure that my work, personal life, and contributions don’t clash. Of course, I also try to stay flexible; some weeks are more demanding than others, but having a framework keeps me grounded and ensures I can keep giving my best to Git.
Can you share how Outreachy helped enhance your technical and non-technical skills (like communication, project management, etc.)?

My C and low-level engineering skills have improved immensely through this experience. I now feel much more confident working in a large and complex codebase, and I’ve built the mindset to take on hard problems without shying away. This confidence is what’s encouraging me to dive deeper into the Linux kernel, where I’ve been learning and experimenting with the graphics stack and GPU drivers. My knowledge of Git itself has also grown significantly, particularly with the interactive rebase functionality, which has completely changed how I think about version control and history management.

On the non-technical side, I grew a lot in communication and project management. I learned how to break down tasks into smaller, achievable goals, track progress against deadlines, and ask for help effectively when I was stuck. Collaborating with mentors and the wider Git community also taught me the importance of giving clear updates in blog posts and writing thoughtful commit messages.

Overall, the experience didn’t just make me a better programmer; it made me more disciplined, collaborative, and confident in working on real-world projects.
What was your biggest takeaway or learning from Outreachy that you now apply regularly in your work?

My biggest takeaway from Outreachy is the balance between understanding deeply and taking action. My mentor encouraged me to not just know how things work but also to dig into why they work. At the same time, I learned that it’s easy to get stuck in the learning phase, waiting until you feel “ready.” During my first few weeks, I hesitated too much. What really helped me was realizing that you don’t need to know everything before you start; you just need enough to begin, and the rest comes as you build and iterate. That shift has stayed with me and is something I now apply regularly in my life.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

One of the biggest challenges I faced was understanding the Git codebase. Git is a very large and complex project with many interconnected parts, and even though my task was limited to the unit testing section, I also needed to understand the underlying functionality being tested. At first, it felt daunting, but I overcame this by burning the midnight candle, digging deeper, and committing myself to continuous learning. Bit by bit, things started to make sense. What really helped was breaking down the complexity into smaller pieces and focusing on one area at a time, while also asking lots of questions and referring back to documentation.
Have you thought about mentoring new GSoC / Outreachy students?

Yes, I hope to mentor future Outreachy interns if the opportunity arises.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

A first-class graphical interface officially maintained by the Git project, for those who prefer using an app instead of the command line.
What upcoming features or changes in Git are you particularly excited about?

I’ve been reading recent discussions on the Git mailing list about how Git might evolve in the age of AI, particularly around enabling integrations with AI agents. The idea of extending Git’s capabilities so that AI tools can better understand, interact with, and even automate certain workflows is quite exciting. For example, AI-assisted code reviews, intelligent merge conflict resolution, or automated repository maintenance could become more seamless if Git had standardized ways for agents to plug into its internals.
What is your favorite Git-related tool/library, outside of Git itself?

GitHub and GitLab.
What is your toolbox for interacting with the mailing list and for development of Git?

I mostly work from the command line. For sending contributions, I use git format-patch and git send-email, since I’m more comfortable with CLI tools.
How do you envision your own involvement with Git or other open source projects in the future?

I intend to remain active in the Git community for many years by making steady contributions. At the moment, I’m still learning and exploring the project to identify areas where I can improve and add value. Over time, I hope to grow into a consistent contributor and take on more responsibility within the project.
What is your advice for people who want to start Git development? Where and how should they start?

For anyone starting Git development, I’d recommend a few key resources. The “Hacking Git” guide is definitely a go-to resource for understanding how the project is structured and how to navigate the codebase. The MyFirstContribution page is also very helpful for learning how to get started with making changes. Beyond that, the general Git documentation is valuable for building a solid foundation. Starting small, asking questions, and getting familiar with these resources can make the process much smoother.
Would you recommend other students or contributors to participate in the GSoC, Outreachy or other mentoring programs, working on Git? Why? Do you have advice for them?

100% yes. Programs like GSoC and Outreachy give you the unique opportunity to learn directly from some of the smartest and most experienced contributors in the Git community. Having a mentor to guide you through real contributions accelerates your learning, helps you build confidence and good practices early on. I’d absolutely recommend it. My advice would be: come with curiosity, patience, and the willingness to learn. Don’t worry if you don’t understand everything at first. Ask questions, read the documentation, and engage with the community. The mentorship and the experience you gain are invaluable.

Other News

Various

What’s new in Git 2.51.0? by Karthik Nayak on GitLab Blog. It describes performance optimizations for git push and git fetch (most significant when using the “reftable” backend for references), further plans for Git 3.0 (which can be found in the BreakingChanges document), semi-removal of git whatchanged (still available with --i-still-use-this flag), and marking git switch and git restore as no longer experimental, adding a new --start-after flag for git for-each-ref (that can be combined with the --count flag to support pagination), etc.
Highlights from Git 2.51 by Taylor Blau on GitHub Blog. It describes cruft-free multi-pack indexes (which currently require setting a new repack.MIDXMustContainCruft config option), smaller packs with a “path walk” method of collecting objects when repacking (which you can try out with the new --path-walk command-line option), a variant of the internal stash representation that can be used for stash interchange (with new export and import commands for git stash), etc.
Xet is now the default storage option for new users and organizations at Hugging Face, switching from Git LFS. This includes moving existing repositories from LFS to Xet. To get the most out of Xet storage read the usage instructions in the Hub docs. Note that Xet remains backward compatible with legacy clients optimized for Git LFS.
- XetHub was first mentioned in passing in Git Rev News #95, and its benchmark by XetHub against S3, DVC, and Git LFS was mentioned in Git Rev News Edition #113.
- Compare with DagsHub launching Direct Data Access in 2022. DagsHub was first mentioned in Git Rev News Edition #72, then in #85, #96, #107, and #113.

Light reading

The future of large files in Git is Git by Tyler Cipriani on his blog. It describes how one can use partial clone today (and large object promisors in the future, which are work in progress) instead of using Git LFS or similar solutions like git-annex (or no longer actively developed solutions like git-media and git-fat) or DVC (Data Version Control).
Code Review Can Be Better (than GitHub’s default code review process) by matklad (Alex Kladov) on the TigerBeetle blog.
Mentions their git-review work-in-progress tool, and also the
- Fossil version control system with built-in project management (first mentioned in Git Rev News Edition #11), the
- NoteDb backend for Gerrit - which allows storing review state in Git, (NoteDb was first mentioned in Git Rev News Edition #40), the
- git-bug tool that uses Git to store information about issues / bugs (first mentioned in Git Rev News Edition #43), the
- git-appraise tool that uses Git to store information about reviews (first mentioned in Git Rev News Edition #11), the
- prr (‘pull request review’) tool that brings mailing list style code reviews to GitHub PRs (mentioned in Git Rev News Edition #90), the
- git-pr project that leverages Git native features to replace the entire pull request workflow, (mentioned in Git Rev News Edition #113), and the
- How Jane Street Does Code Review article by Ian Henry on Jane Street Tech Talks site.
Jujutsu + Radicle = ❤️ by fintohaps on Radicle Blog, describing how the author uses Jujutsu in tandem with Radicle.
- Jujutsu (jj) is a Git-compatible version control system written in Rust, and was first mentioned in Git Rev News Edition #85.
- Radicle, a peer-to-peer, local-first code collaboration stack built on Git, was first mentioned in Git Rev News Edition #49.
introducing spindle by Anirudh & Akshay on Tangled blog; spindle is Tangled’s new CI runner built atop Nix and the AT Protocol.
- Tangled.sh is a new social-enabled Git collaboration platform built on top of the AT Protocol (which is behind BlueSky microblogging federated social media service). First mentioned in the previous edition of Git Rev News.
- Compare the Using Radicle CI for Development article by Lars Wirzenius, also mentioned in Git Rev News #125. Radicle is another distributed Git hosting system, first mentioned in Git Rev News Edition #49.
How we used Radicle with GitHub Actions: Quick guide to trying Radicle without dropping GitHub or whatever CI you’re using. Published by rudolfs (Rūdolfs Ošiņš) on Radicle Blog.
Archive Legacy GitHub Repos with Subtree by Tony Metzidis on DEV.to, about how to use git subtree to consolidate hundreds of legacy experimental repos into an archive, preserving all of the commit history.
I’ll think twice before using Github Actions again by Nemanja Ninković on their blog.
Git without a forge by Simon Tatham on his quasiblog, describing how to interact with a bare Git repo, and explaining why he personally does not use any of the Git forges.
How I Cleaned Up My Git History Like a Boss (a.k.a. Fixing Wrong Author Emails) by Emrah G. on DEV.to. The solution uses the (deprecated) git filter-branch tool; the recommended replacement is git filter-repo. Also, you can correct the visible e-mail with the .mailmap file (changing what Git shows, without having to rewrite history).
Revolutionizing Git Workflows: The MCP Git Commit Generator by Theoklitos Bampouris on his blog (and also on DEV.to), about using Agentic AI and an LLM chatbot, leveraging the Model Context Protocol (MCP). The generated commit message will follow Conventional Commits conventions.
Note: please read the proposed commit message before accepting it, especially for more complex changes. While AI agents can take information from changes and from an issue tracker, they cannot write whys of the change; they cannot access your thoughts.
- Git Rev News Edition #97 lists a few other tools that use the GPT-3 / ChatGPT Large Language Model (LLM) to help write commit messages.
Better git status by James (@purpleidea) on his blog. He uses git alias which examines the terminal width, and then git status --column=nodense if the terminal is wide enough.
Some Pretty Cool Git Tools To Save Your Sanity by Charles Féval on his blog. Mentions git revise for splitting pull requests (PRs), and custom git backup, git reparent, git split, git move-branch, and git bookmark commands.
Using Git worktrees for development by Igor Kulman on his blog.
Curing A Case Of Git-UX by Akshay on their blog; describes how one can improve git worktree UX with the help of fzf (or skim or fzy), and shell functions.
- See also Improving shell workflows with fzf, mentioned in Git Rev News Edition #74.
Making my GitHub heatmap widget by Lean Rada on their blog. The created tool partially scrapes and reformats HTML input, but is constructed in such way that it could consume JSON from GitHub API instead.
TryHackMe - Git Happens by Jacen Sekai on his blog, about Git Happens: an easy-ranked box on TryHackMe, website for hands-on cyber security training through real-world scenarios.
The Ingredients of a Productive Monorepo by Sean Gillespie on his blog.
- You can find a definition of “monorepo” and a list of various tools on the Monorepo.tools site, which was first mentioned in Git Rev News Edition #84.
Git Branching Explained: Base, Topic, and Parent Branches by Bruno Brito on Tower Blog.
Git and jujutsu: in miniature by Charlotte (lottia) on her blog (2024).
Git Interactive Rebase TODO Order is Wrong by Sal Ferrarello on his blog (2019), stating a personal preference for stack-like order, with latest commits appearing on the top.
The author even wrote a Vim plugin, Interactive Rebase Reverse Vim, to reverse the order of the commits in an interactive git rebase.
Every line of code is always documented by Mislav Marohnić on his blog (2014). The article describes how to extract information about a code snippet from project history using git blame, ‘pickaxe’ search with git log -S, and a git-churn script, and how to stay on the right side of history (among others, to be able to use this technique effectively).

Git tools and sites

WRKFLW is a command-line tool for validating and executing GitHub Actions workflows locally, without requiring a full GitHub environment. It helps developers test their workflows directly on their machines before pushing changes to GitHub. Written in Rust, under MIT license.
- Compare with the Act command line tool to run your GitHub Actions locally, using the Docker Engine API. Written in Go, under MIT license. Mentioned in Git Rev News Edition #113.
Setup DVC Action by Iterative is a JavaScript action that can be used as a step in GitHub Actions.
DVC (Data Version Control) was first mentioned in Git Rev News Edition #42 and many times since (most recently in Edition #116).
Lappverk is a tool for modifying other people’s software. It works by keeping a series of .patch files as its source of truth (like quilt), but using temporary Git repositories as an interface to modify the patches, rather than implementing its own version control system from scratch. Written in Rust, under Apache 2.0 License. Started out as Patchable internal tool.
You might also be interested in reading the announcement blog post: Modifying Other People’s Software by Natalie Klestrup Röijezon (natkr) on natkr’s ramblings.
- Compare patchwork - a web-based patch tracking system designed to facilitate contribution and management of contributions to an open-source project, first mentioned in Git Rev News Edition #20.
- Compare Stacked Git (StGit), an application for managing Git commits as a stack of patches, first mentioned in Git Rev News Edition #17.
- Compare B4 Tools, a helper utility to work with patches made available via a public-inbox archive like lore.kernel.org. This tool is written to make it easier to participate in patch-based workflows, like those used in the Linux kernel development. First mentioned in Git Rev News Edition #61.
patch-hub is a TUI tool that streamlines the interaction of Linux developers with patches archived on lore.kernel.org. Written in Rust, under GPL 2.0 license.
It is a spin-off of kw, a tool for helping Linux kernel developers in everyday tasks (which is written in shell, and is under GPL 2.0 license).
GitGenius is a smart and simple CLI tool that explains Git errors in plain English and helps you fix them quickly. Written in Python, under MIT license.
- See also thefuck, a command line application which corrects your previous console command (for example Git command) if you made an error (like typos in command name), and it didn’t do what you wanted; the tool was first mentioned in Git Rev News Edition #101.
- Compare the Oh Shit, Git!?! / Dangit, Git!?! website by Katie Sylor-Miller, first mentioned in Git Rev News Edition #19.
GIT.WTF!?! is a website with articles in which you can find solutions to your Git problems, along with tips & tricks to improve your Git workflows.
GITHUB2FORGEJO is a Bash script for migrating all repositories from a GitHub user account to a specified Forgejo instance. It supports mirroring or one-time cloning and includes a cleanup feature for removing repositories on Forgejo that no longer exist on GitHub. Under GPL 3.0 license.
Based on GitHub2Forgejo Nushell script, also under GPL 3.0 license.
- Forgejo is a self-hosted lightweight software forge, which started as a “soft” fork of Gitea (itself a fork of Gogs), and was first mentioned in passing in Git Rev News Edition #103.
git-revise is a Git subcommand and Python library for efficiently updating, splitting, and rearranging commits. Under MIT License.
The Introducing git-revise blog post was mentioned in Git Rev News Edition #54.
git-tools is a set of additional Git commands to “help you make crazy stuff in a very unsafe way”. Includes git backup, git move-branch, git reparent (similar to git rebase --onto), git split, git bookmark, git newbranch, and git get. Written in Go, under GPL 2.0 license.
git-fetch-file is a utility for importing specific files from other Git repositories into your own project, while keeping a manifest (.git-remote-files) that remembers where they came from and what commit they belong to. Written in Python, under GPL 2.0 license.
git-word-blame is a tool that shows word-by-word authors of a file, creating TSV and HTML files. Written in Python, under GPL 3.0 license. The README includes links to a few alternative tools in the “See also” section.
gguser is a CLI tool to easily switch between different Git user profiles. It simplifies managing multiple GitHub or GitLab accounts by allowing users to switch between profiles effortlessly. Written in JavaScript for Node.js (npm), under Apache 2.0 License.
GitLabForm is a specialized configuration-as-code tool for GitLab’s application settings, groups, projects, and more, using hierarchical configuration written in YAML. Written in Python, under MIT license.
See the GitlabForm for Gitlab repository automation blog post by Mike Street on his blog.
gmap is a fast command-line tool (with terminal interface) to explore Git activity - heatmaps, churn, authorship, and more. It helps you understand your Git repository at a glance - not just what changed, but when, how much, and by whom. Written in Rust, under MIT license.
Ayllu is a code forge optimized for single instance deployments. It is still a work in progress. Written in Rust, under AGPL license.
DiffMem is a lightweight, Git-based memory backend designed for AI agents and conversational systems. It uses Markdown files for human-readable storage, Git for tracking temporal evolution through differentials, and an in-memory BM25 index for fast, explainable retrieval. This project is a proof-of-concept (PoC). Written in Python, no license (!).

Releases

Git 2.51.0, 2.51.0-rc2, 2.51.0-rc1, 2.51.0-rc0
Git for Windows v2.51.0(1), v2.51.0-rc2(1), v2.51.0-rc1(1), v2.51.0-rc0(1)
GitLab 18.3.1, 18.2.5, 18.1.5, 18.3, 18.2.4, 17.11.7, 18.2.2, 18.1.4, 18.0.6
Gerrit Code Review 3.10.8, 3.11.5, 3.12.2
GitHub Enterprise 3.17.5, 3.16.8, 3.15.12, 3.14.17
GitKraken 11.3.0
Git Cola 4.14.0
GitButler 0.15.16, 0.15.15
Sublime Merge Build 2112
Tower for Mac 14 (YouTube video)
Kinetic Merge 1.9.0

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Štěpán Němec, Gerard Murphy, Seyi Kuforiji and Bruno Brito.

Git Rev News Edition 125 (July 31st, 2025)

chriscool — Thu, 31 Jul 2025 11:06:51 +0000

Git Rev News: Edition 125 (July 31st, 2025)

Welcome to the 125th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of June and July 2025.

Discussions

General

20 years ago: Meet the new maintainer..

On July 26 2005, so 20 years ago, Linus Torvalds announced on the mailing list that Junio Hamano accepted the maintainership of the Git project and that Junio “was the obvious choice”. Linus said he wasn’t dropping Git but he just preferred working on it as a contributor.

Junio replied with an A note from the new GIT maintainer email where he acknowledged his new role as Git maintainer, thanked the community for their support and collaboration, and promised to take a more careful and deliberate approach in shepherding the project. He also said he would post his own patches to the mailing list for review before including them in the repository, and encouraged community feedback.
[ANNOUNCE] Git Mini Summit at Open Source Summit Europe, Amsterdam, August 28th

Patrick Steinhardt announced a Git Mini Summit co-located with the Open Source Summit Europe in Amsterdam on August 28th 2025.

There will be lightning talks and some time for people to connect. Proposals for the lightning talks should be sent to Patrick, while the possibility to have remote talks is still investigated.

Registration is open for both the Git Mini Summit only and for the Open Source Summit Europe including the Git Mini Summit.

Reviews

[PATCH v4 0/3] send-email: add oauth2 support and fix outlook breaking threads

Last April, Aditya Garg sent a patch series containing three main changes to git send-email. He mentioned that he was sending the email series using the very patches he was proposing, via Outlook.

The first patch was a rebased version of an earlier patch by Julian Swagemakers adding support for OAuth2 authentication, which started to be required by Microsoft. Julian’s patch unfortunately had been waiting for review for over a year before Aditya picked it up.

The second patch fixed thread breaking caused by Outlook’s proprietary Message-ID handling.

The final patch added a new option for generating passwords, such as OAuth2 tokens, via an external script.

Junio Hamano, the Git maintainer, reviewed the three patches saying he liked the commit messages, documentation and code comments even though he suggested a few small style improvements to the code style plus a number of grammar and formatting changes to the documentation.

He also asked for reviews from others as he said he was not familiar with the Authen::SASL library.

Aditya replied to Junio’s review acknowledging the need for more reviews and saying that OAuth2 was a significant and more secure technology. He then took the initiative to Cc Greg Kroah-Hartman, who wrote a precursor of git send-email for the Linux kernel.

M Hickford also replied to Aditya expressing enthusiasm for the work but wondering why the v4 version of the patch series was sent in a new email thread rather than as a reply to the previous version.

brian m. carlson commented on the second patch saying that replacing message IDs like Outlook does is technically allowed by standards. They raised concerns about hardcoding only two Outlook server hostnames, and suggested adding configuration options for Message-ID generation modes.

Julian Swagemakers then pointed out that the goal of the third patch could already be achieved using Git’s existing custom credential helper mechanism. Aditya confirmed this worked and said he was unaware of this feature, which led to the decision to drop the third patch. Recognizing that the existing feature was poorly discoverable, the discussion led to improvements in Git’s documentation, adding clearer examples of using credential helpers for OAuth2 tokens.

Erik Huelsmann, the maintainer of the Authen::SASL Perl module, joined the conversation after Aditya emailed him directly referencing a GitHub issue about the lack of OAuth2 support in Authen::SASL. In that issue Erik had commented that he would be happy to support XOAUTH2, but needed a patch and a way to test it.

Aditya and Julian then worked together, with guidance from Erik, to add the necessary XOAUTH2 and OAUTHBEARER support directly into Authen::SASL. Shortly after, a new version of the Authen::SASL module was officially released with this new functionality. This successful collaboration meant the first patch in the series, which was a workaround for the missing library support, was no longer needed and was subsequently dropped. Instead, the new version of Authen::SASL started to benefit all Perl users.

Greg Kroah-Hartman echoed what brian had suggested about using a configurable solution in the second patch. Greg noted that the initial approach would not cover company-hosted Outlook servers. Yao Zi also contributed to this discussion, noting that Tencent’s mail service had similar issues, further reinforcing the need for a flexible solution beyond just hardcoding specific server names.

That suggestion was then refined by Junio Hamano, who proposed a concrete implementation for the new option by providing an example patch. The final --[no-]outlook-id-fix option auto-detects known Outlook servers but allows manual override for other deployments.

After several iterations on its name and behavior, with Eric Sunshine helping refine the user-facing documentation, Aditya submitted a final, simplified patch series (v6). It now contained only the single, refined patch to fix Outlook thread breaking, with the other two patches having been made obsolete by the Authen::SASL library update and the use of existing Git features.

Aditya’s patch was merged and released as part of Git v2.50.0.

Developer Spotlight: Usman Akinyemi

Who are you and what do you do?

I’m Usman Akinyemi, a final-year CS and AI student, and an open-source contributor passionate about Linux, distributed systems, and developer tools. I’ve contributed to core projects like Git, systemd, LLVM, and LibreOffice. During my Outreachy internship, I improved Git’s v2 protocol by adding OS-level metadata for better diagnostics and security.

Currently, I’m a Google Summer of Code contributor building a containerized pipeline for medical imaging using Kaapana, Kubernetes and Airflow. I am also currently working on creating a new subtype for RISC-V assembly instructions through the Linux Foundation’s LFX program.

Outside code, I mentor new contributors, volunteer with DesignIT and LEAD and CODE to teach digital skills, and organize a tech webinar for Nigerian students. I’ll be speaking at Git Merge 2025, sharing insights from my open-source journey. I believe in the power of community, collaboration, and curiosity to build a career that crosses borders.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your Outreachy project?

Though I have been contributing to other projects before applying for Outreachy (Dec 2024), I was just a user of the Git project. When it comes to the Outreachy contribution period when I had to pick a project, I picked both Git and LibreOffice. I picked Git as it is a project I use every time, also the thought of contributing to a project used by almost all the developers in the whole world was definitely a dream coming true. To also maximize my getting selected for Outreachy, I picked Git because it is written in C, which many other participants are always scared to pick (going for the hard thing). The story did not end there as I got selected for both LibreOffice and Git and I had to choose one as my Outreachy projects. It was a hard decision but I picked it mainly because the Git community is a community where it is so easy to communicate with other team members, and it is a community where I clearly know who is who and what they do in the community. Also Git is more well recognised.
How do you feel your contribution has impacted the Git community or the broader open source ecosystem?

My contribution makes a fundamental improvement to the Git v2 protocol by enabling Git clients to share their operating system information via the user agent string. This helps platforms like GitHub, GitLab, and others gain visibility into which OS environments are interacting with their servers. It significantly improves debugging, security auditing, and telemetry, helping maintainers understand usage patterns and tailor support or upgrade strategies accordingly. Since this change is part of the core Git client, it means it is used by all Git users. I’m proud to have contributed something with such wide-reaching, foundational impact.
Is there any aspect of Git that you now see differently after having contributed to it?

Before contributing to Git, I saw it as a complex tool that “just works”. Although I knew Git was different from GitHub, I struggled to clearly differentiate between the two. But after contributing, I could clearly differentiate between the two and I now see Git as a carefully designed software project with a strong emphasis on performance, cross-platform compatibility, and community-driven development.

I’ve come to appreciate the level of thought and care that goes into every change, from writing clean patches and commit messages to engaging in technical discussions and defending your design decisions.

Contributing to Git isn’t also about hierarchical review; instead, it’s a collaborative process where every contributor is expected to take full ownership of their patches, understand the problem they are trying to fix, the solution and explain their rationale clearly by writing clean patches, commit messages and engaging in technical discussions and defending your design decisions. In fact, there have been moments when some of my contributions led to insights even long time contributors hadn’t considered, including Junio Hamano. That boosted my confidence not just in contributing to Git, but to other software projects as well, i.e., I can get my patches accepted anywhere, I just need to convince others that it actually solves a problem.
How do you balance your contributions with other responsibilities like work or school?

Seriously, it has not been easy, most of my contributions to all open source projects have always been during college. But, I have sort of made contributions to open source as one important aspect of my life and also as a way to learn new technologies and also practice whatever new skills I learnt. Contributing to projects millions of people use is also definitely rewarding and satisfying.
Can you share how Outreachy helped enhance your technical and non-technical skills (like communication, project management, etc.)?

Technically, I have been able to improve my C programming and bash scripting skills. Also reading and understanding very large codebases like Git. Of course now I can call myself an expert in using Git as a tool itself.

To contribute to Git, you must be able to communicate well, as all the Git workflows happen remotely and over mailing lists. Most of the time in the Git community it is not about the correctness of your code – it is about how well you can communicate your rationale to the community before your patches can be accepted. So, over time, as a Git contributor, my communication skills in a technical environment have really improved.

I have also learnt to write clean code, organize my changes into well formatted patches, and write clear commit messages.
What was your biggest takeaway or learning from Outreachy that you now apply regularly in your work?

I’d say my biggest takeaway from Outreachy is learning how to write clear, structured commit messages. Git commits, like those in the Linux kernel, follow a thoughtful format: describe the current state, the problem, and the fix. From reading most of the commit messages in Git, you would have understood and been able to visualize what the changes will look like. It also makes it easy to track the changes to other prerequisite commits. I have been using the Git commit messages format in other projects and I really love it.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

I think the challenge which I initially faced is sending patches to Git, not really a big challenge though as I was able to make my first patch in a few days after joining the community. And the reason is that Git does not use GitHub or GitLab, something someone would have thought they will be using. Git uses a mailing list just like the Linux kernel. While writing this, I remember that I had a challenge retrieving patches from the mailing list as my project depended on some patches that were sent by my mentor previously. I had to use git am, something I never used before. Help from my mentor really helped, as well as reading through the “Hacking Git” page.
Have you thought about mentoring new GSoC / Outreachy students?

Yeah, I am planning to put in as a mentor for the coming Outreachy period and hopefully for GSoC also. I will be starting as a co-mentor though.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Smile, I will definitely say the Rustication of some parts of Git which has been going on currently, I think one that has already been integrated to Git is libgit-rs. Rust seems to be a language that focuses more on safety/security, and safety/security is very important in Git. I am also a Rustacean so I should be able to help hopefully if that happens.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I really do not have anything in mind for now.
What upcoming features or changes in Git are you particularly excited about?

I think it is one of the GSoC projects by Lucas. I have been passively following the project. It is about introducing a new Git sub-command (currently intended to be called git repo-info) that will centralize data currently retrieved by git rev-parse in a JSON format.
What is your favorite Git-related tool/library, outside of Git itself?

I think it’s both GitHub and GitLab – if I have to choose one, I will say GitHub.
What is your toolbox for interacting with the mailing list and for development of Git?

I started with GitGitGadget initially just to get my patches to the mailing list faster but, along the line I switched to git send-email and really, it is more flexible and easy to use than I thought of it. For my machine, I basically use Arch Linux and Neovim as my text editor.
How do you envision your own involvement with Git or other open source projects in the future?

As I said earlier, open source has really been part of my life and it has really helped me a lot in improving my skills, meeting new people and even making some few bucks through internships. After my internship at Outreachy, I did send patches to the Git community and I planned to keep doing that. After Outreachy, I have contributed to a few other projects like RISC-V and OSIPI (through GSoC). I currently mentor people who want to start their open source journey, and I plan to do more of it. I planned to keep contributing to open source projects and hopefully get a job in open source.
What is your advice for people who want to start Git development? Where and how should they start?

I have been in many open source projects and see how their workflows are, I will definitely say Git is one of the easiest and most interesting projects to contribute to. The community members are really supportive. Seriously, it is one of the best open source communities I have been to. The best place to start is going through the “Hacking Git” page. It has all the information on how to start contributing and you can make your first contribution to Git. You should generally start with a microproject which aims to introduce you to the Git contribution workflow. Everything can be found above. Making your first contribution to Git is actually very much easier than you might have thought. Also, do not be scared to ask for help, Git developers are always ready to render help.
Would you recommend other students or contributors to participate in the GSoC, Outreachy or other mentoring programs, working on Git? Why? Do you have advice for them?

Definitely, Outreachy and GSoC are very much interesting mentoring programs to start your open source journey. They both really make it easy to start contributing to open source. You get assigned to mentors who are experts in open source and the organization. It is a way to get skills you will never be able to get in your classroom and skills needed to thrive and excel in the software engineering world. Apart from skills, it is a way to have proof of work before graduation and also gain global recognition. As I have said, Git is a well known and recognized software project in the whole world, contributing to it is an achievement on its own.

Shout session

I would like to shout out to all Git contributors, you are doing a great job! I would also like to shout out to my Outreachy mentor Christian Couder, he was really supportive during my Outreachy program! Thanks to the Git Rev teams also!

Other News

Various

[LWN.net] A set of Git security-fix releases by Jonathan Corbet on LWN.net, and
Multiple vulnerabilities fixed in Git by Taylor Blau on oss-security mailing list.
[ANNOUNCE] Git v2.50.1 and friends by Junio C Hamano on the Git mailing list.
Launchpad is phasing out Bazaar code hosting. This post provides a link to the Migrate a Repository From Bazaar to Git article.

Light reading

Artisanal Handcrafted Git Repositories by Drew Silcock on drew’s dev blog. This article talks about how to handmake your Git repositories without using git commands. You might also learn a bit more about how Git works under the hood during the process.
How to use git worktree effectively with Python projects (with the help of a simple git-add-worktree.sh Bash script) by Andrea Grandi on his blog.
Managing Multiple Claude Code Sessions Without Worktrees by Scott Chacon on Butler’s Log (GitButler Blog). With Claude Code’s new lifecycle hooks, GitButler Git client auto-sorts simultaneous AI coding into separate branches, without manual use of git worktree. With this feature you can write three features, and get three clean branches.
wtp: A Better Git Worktree CLI Tool by Satoshi Ebisawa on DEV.to. The wtp tool was created to make working with multiple tasks in parallel using Claude Code easier than with git worktree.
Automated repo maintenance via GitHub Copilot coding agent by Pamela Fox on her Blogger-based blog.
Git Worktrees: Git Done Right by Nick Taylor on Just Some Dev blog (and also on DEV.to).
I Lost My Git Stash, So I Built a Tool (VS Code Extension) to Share It by Karandeep Singh on DEV.to.
Git: share a full repository as a file with git fast-export by Adam Johnson on his blog (for some reason the post does not mention the alternative of using git bundle).
- Adam Johnson is the author of “Boost Your Git DX” book, first mentioned in Git Rev News Edition #104, then its updates in #110 and #119.
Conventional Commits makes me sad by Sarah Mathey on her Codeberg Pages powered Sarah’s Website blog.
The Conventional Commits specification was first mentioned in Git Rev News Edition #52.
Git experts should try Jujutsu by Pavan Sunkara on his personal blog.
Jujutsu (jj) is a version control system first mentioned in Git Rev News Edition #85.
Jujutsu For Busy Devs and by Madeleine Mortensen on her personal blog.
Using Radicle CI for Development by Lars Wirzenius on Radicle Blog.
Radicle is the distributed git hosting system, first mentioned in Git Rev News Edition #49.
Cutting GitHub out of the loop (by deploying to a VPS with Git and SSH). Written by tomjuggler on The Circus Scientist Site.
Super Easy* 2-Stage Git Deployment by Dave Gauer on Dave’s Virtual Box of Cards.
Guest Post: How I Scanned all of GitHub’s “Oops Commits” for Leaked Secrets by Sharon Brizinov on The Dig, the Truffle Security blog.
Top 17 Essential Git Tools for Enhanced Developer Productivity by vAlber on DEV.to.

Git tools and sites

DiffX - Next-Generation Extensible Diff Format: describes problem with Unified Diff format, and proposes as a solution a new file format specification for Extensible Diffs, fully backwards-compatible with existing tools, while also being future-proof and remaining human-readable.
git-phoenix is a command line tool that does repository recovery after accidental removal or file system failure, using photorec (or similar tool). Written in Haskell, under 3-clause BSD license.
wtp (Worktree Plus) is a Git worktree management tool that extends git’s worktree functionality with automated setup, branch tracking, and project-specific hooks. Written in Go, under the MIT license.
GitNifty is a robust and promise-based Git utility for Node.js, offering developers smart, automation-ready commands for common Git operations. Created for building CLI tools, automation scripts, or custom Git workflows. Written in TypeScript, and released under the Apache License.
difit is a CLI tool that lets you view and review local git diffs with a GitHub-style viewer (in a browser). Written in TypeScript, under MIT license.
See difit: Preview GitHub-like diffs locally before you push by Yuji Ueki on DEV.to.
Flint is a Git-integrated code formatter that lets each developer work in their preferred style locally, while maintaining a consistent style remotely. By automatically applying “local” and “remote” formatting passes during pull and push operations, Flint prevents formatting noise in commits and code reviews. It is currently in alpha and is available exclusively on npm. Written in Bash, under MIT license.
DotProj is a developer-centric CLI tool designed to manage project-specific configuration files with Git versioning. It helps keep your development environment settings organized, versioned, and synchronized across multiple machines and projects. DotProj uses Git commands (commit, push, pull, clone) making it intuitive for developers. Written as a Bash shell script, under MIT license.
git-remote-sqlite is a Git protocol helper that helps you store a Git repository in a SQLite database. Written in Zig, under MIT license.
Backlog.md is a tool that turns any folder with a Git repo into a self-contained project board, powered by plain Markdown files and a zero-config CLI. Written in TypeScript, under MIT license. AI ready.
git-resolve.sh is a Bash script that resolves a short git commit ID to its full SHA-1 hash, which is particularly useful for fixing references in commit messages. Under GPL-2.0 license.
GitHub Trends is a service that uses the GitHub API to bring you insightful metrics on your contributions, broken by repository and language.
DeepWiki: AI-generated docs for any repo. This service turns any public GitHub repo into up-to-date documentation you can talk to (see for example DeepWiki: git/git. DeepWiki is the free public version of Devin Wiki and Devin Search.
There are a few similar projects, like Open Source DeepWiki and OpenDeepWiki.
GitHub Repository Maintenance Agent is an AI-powered agent for triaging failed Dependabot pull requests across one’s GitHub repositories. The agent uses Pydantic AI for LLM-based decisions and the GitHub API for repository, PR, and issue management. Written in Python, under MIT license.
tangled is a new social-enabled git collaboration platform built on the AT Protocol (that powers the Bluesky social network). Written in Go, under MIT license; note that it is in alpha stage of development.
Compare with:
- Radicle, a peer-to-peer, local-first code collaboration stack built on Git (first mentioned in Git Rev News Edition #49).
- ForgeFed (formerly GitPub), a federation protocol for software forges (first mentioned in Git Rev News Edition #69).
- git-ssb (see the git-ssb-intro guide), a decentralized Git repo hosting and issue tracking on Secure-ScuttleButt (SSB) (first mentioned in Git Rev News Edition #26.
- gitstr (git str), a tool to send and receive Git patches over Nostr, using NIP-34 (first mentioned in Git Rev News Edition #109).
Git With Me is a tool for peer-to-peer, encrypted, ephemeral Git collaboration. git withme provides a way for a single host to invite numerous peers with short, one-time secure codes. The peers connect directly via Dilated Magic Wormhole channels, allowing collaborators to git clone git://localhost/<repo-name>.
Radicle Desktop is a desktop application that lets you interact with Radicle, a peer-to-peer code collaboration and publishing stack. Written in TypeScript for Node.js and Rust, using the Tauri framework. Under GPLv3 license.
GitBug: Git Learning Simulator is a CLI app that teaches Git through hands-on bug fixing. It uses a realistic merge conflict scenario with visual feedback at every step. The goal of the app is to help you learn by doing, not just reading. Written in Python, under MIT license, in early stage (alpha).
Compare with:
- Learn Git Branching, mentioned first in Git Rev News Edition #30.
- Git Gud, a visual web-based Git simulator, meant to help understand Git better, announced by its author Nic Hartley in Git Gud at git. First mentioned in Git Rev News Edition #48.
- Git Gud, a command line game designed to help you learn how to use the Git version control system. Written in Python by Ben Thayer. First mentioned in Git Rev News Edition #72.
- Oh My Git!, an open source game about learning Git, written using the Godot game engine (source). There was a lightning talk about this game at FOSDEM 2021: Building a Git learning game: A playful approach to version control. First mentioned in Git Rev News Edition #72.
- Git-Sim tool (written in Python) to visually simulate Git operations in your own repos with a single terminal command. Described in Git-Sim: Visually Simulate Git Operations In Your Own Repos (mentioned in Git Rev News Edition #95) and Git-Sim 3 Month Dev Update: Community Response, New Features, & The Future (mentioned in Edition #98).
- Visualize Git web app that illustrates what’s going on under the hood when you use common Git operations, first mentioned in Git Rev News Edition #107.
- Devlands, which is the game that creates immersive experience to help learning Git. First mentioned in Git Rev News Edition #122.
Ferriby is a CLI game where you try to keep Ferrises alive and happy by feeding them commits in your repositories. Written in Rust, under MIT license.
Pride Versioning, a joking take on Semantic Versioning (SemVer).

Releases

Git 2.50.1 and friends
Git for Windows 2.50.1(1), 2.50.0(2), 2.49.1
GitHub Enterprise 3.17.4, 3.16.7, 3.15.11, 3.14.16, 3.17.3, 3.16.6, 3.15.10, 3.14.15, 3.17.2, 3.16.5, 3.15.9, 3.14.14
GitLab 18.2.1, 18.1.3, 18.0.5, 18.2, 18.1.2, 18.0.4, 17.11.6
Gerrit Code Review 3.10.7, 3.11.4, 3.12.1
GitKraken 11.2.1, 11.2.0, 11.1.1, 11.1.0, 11.0.0
GitHub Desktop 3.5.2, 3.5.1
Sourcetree 4.2.13
GitButler 0.15.8, 0.15.7
Sublime Merge Build 2110
Tower for Mac 13.1
Tower for Windows 9.1 - YT video

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Usman Akinyemi, brian m. carlson, Aditya Garg, Erik-B. Ernst, Bruno Brito and Štěpán Němec.

Git Rev News Edition 124 (June 30th, 2025)

chriscool — Mon, 30 Jun 2025 11:06:51 +0000

Git Rev News: Edition 124 (June 30th, 2025)

Welcome to the 124th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of May and June 2025.

Discussions

Support

[BUG] git stash incorrectly showing submodule branch instead of superproject branch

Stuart MacDonald sent a bug report to the mailing list. The report described a workflow where people worked on a UI project that included a hardware SDK as a submodule. Both the UI project (the “superproject”) and the SDK project (the submodule) had their own branches.

When using git stash on a bug fix branch on the superproject, while the submodule was on a feature branch, it appeared that the command git stash list output a message, like:

stash@{0}: On feature_sdk_foo: debugging

indicating the stash had been created on the submodule’s branch instead of the superproject’s branch. The branch feature_sdk_foo didn’t even exist in the superproject.

Stuart mentioned he thought this used to work correctly around 2021, though he wasn’t 100% certain.

K Jayatheerth replied to Stuart confirming the bug happened on different OSes, showing minimal steps to reproduce it, and saying it was “one of the most interesting Git bugs” he had seen in a while.

Jayatheerth came back later with a patch that fixed the bug. It appeared that the branch name was obtained via the refs_resolve_ref_unsafe() function, which returns a pointer to a static buffer, but that static buffer was overwritten. To fix this, the patch copied the branch name instead of pointing to the static buffer.

Stuart thanked Jayatheerth even though he couldn’t rebuild Git with the patch.

Junio Hamano, the Git maintainer, replied to the patch with small suggestions, while Eric Sunshine noted that the change should also be accompanied by a new test.

Jayatheerth replied to Eric and Junio saying he would fix the small issues and add tests, which he later did in an updated patch.

René Scharfe reviewed the updated patch and suggested a number of improvements to the code and the test.

Jayatheerth then sent a v2 of his patch which addressed René’s comments. Junio reviewed it and suggested further improvements.

The v3 patch from Jayatheerth addressed Junio’s comments and was merged.

Community Spotlight: Luca Milanesio

Luca Milanesio is a long standing contributor to both JGit and Gerrit Code Review, an open-source veteran who’s been accelerating Application Lifecycle workflows for 30+ years—from founding GerritHub.io to pioneering AI-powered repository optimization research.

This is a continuation of our initiative to interview community contributors outside of our mailing list. Our previous interviews were with VonC in edition 106 and Chris Torek in edition 120.

Who are you and what do you do?

My name is Luca Milanesio, and I am the CEO of GerritForge Inc., a company I founded 6 years ago, which is fully dedicated to the development and support of Git and the Gerrit Code Review ecosystem for medium and large enterprises around the globe.

I am a passionate Open-Source contributor, and I have helped many projects grow over my 30+ years of software development career, including Jenkins, JGit, GitBlit, Swagger/Open-API, Kibana, Avro, and Gerrit Code Review.

I am a maintainer and release manager of Gerrit Code Review, a member of its Engineering Steering Committee, and committer of the JGit project.

I introduced GerritHub.io 11 years ago, a free Gerrit Code Review service for all public and private projects on GitHub. It has over 50k subscribers and is currently used by over 300 organisations and open-source projects worldwide.

My latest work is research about using AI, specifically reinforcement learning, to dynamically understand and learn how Git repository metrics evolve and execute actions to improve their performance by up to 100x. The research has been selected for the 50th edition of the IEEE/ACM International Conference on Software Engineering in Ottawa (CA).
What would you name your most important contribution to the Git ecosystem?

I have introduced a multi-site replication plugin between the Git repositories managed by JGit and Gerrit Code Review [ref].

Google introduced the multi-site replication concept in JGit from the very beginning in 2012, with the introduction of DFS, a multi-site distributed storage mechanism for Git. Although DFS was a completely abstract interface layer that could have been implemented on top of any distributed storage, in practice, it was effectively implemented and used only by Google in its internal implementation of JGit.

In the meantime, the rest of the Open-Source community was left with the traditional filesystem-based implementation and its extensions to work effectively and efficiently with a shared filesystem (e.g., NFS). I started using the NFS implementation of JGit on GerritHub.io and contributed many patches and improvements over the years. Still, I was soon hit with all the quirks and limitations of the NFS protocol in trying to mock the “illusion” of a POSIX filesystem over a network protocol, including locking, stale file handles, and caching inconsistencies. After working for 4 years on the NFS implementation of JGit on GerritHub.io on a shared filesystem, I forked the high-availability plugin project and started the multi-site project, which has now entered its 6th year of adoption.

Thanks to the multi-site support, anyone worldwide can use Git replication across Gerrit primary nodes without fearing a split-brain disaster, as it historically happened years ago on a large-scale Git service.
With over 30 years in software development, how have you seen version control systems evolve, and what makes Git stand out in this evolution? ` I started using RCS on my Unix box for tracking the local version of files and avoiding bad surprises, and since then I’ve seen so many so-called revolutions of the version control that promised “the moon” but ended up creating yet another commercial silo. To name a few, consider Rational ClearCase and Perforce, and the legacy they have made for the software industry.

In my experience, version control is the foundation of any Software Development Life Cycle (SDLC for short) and should always be thought of as an evolving technology: I don’t believe that Git is here to stay forever as-is, even though it would be difficult to imagine an Open-Source project starting today not using Git as version control.

But if you roll back to the year 2000, you could have swapped Microsoft with VA Software and Git with Subversion, and asked the same question: `“What version control and hosting site should a new Open-Source project use?” I believe the answer would differ significantly from the one you have today [ref].

What makes Git different from its predecessors is its adoption in large Open-Source projects unlikely to be discontinued any time soon, such as Linux and the Android OS project. With the advent of IoT and the extensive adoption of Android OS everywhere, from appliances to aerospace and automotive, Git version control has become responsible for powering the SDLC of most devices we use daily.

A second factor that has brought Git to the world stage as the future of VCS is its ability to abstract from any vendor bias and be truly driven by only its user base: software developers. Git was invented by Linus Torvalds because he needed it, not because a company X wanted to disrupt the market of the existing version control system Y to achieve goal Z.

A third factor is the growth of other Git-compatible version control systems, such as JJ (aka Jujutsu). Git is, first of all, a data format for versioned directories and BLOBs and a protocol on how this data can be safely transferred between peers: no implementation-specific quirks, no vendor lock-ins, no silos, just data and protocol. This has led other developers, like Martin Von Zweigbergk (Senior Software Engineer @Google), to create version control systems on top of it, assuring interoperability with the existing code and innovation simultaneously.

This is unprecedented and unique in the history of VCSs I have seen in my whole 30+ career as a Software Developer. Do I believe that Git will continue to exist in its current form in 25 years from now? No, I believe it will be very different in the future, but its foundations will remain the same, and I see many more evolutions similar to Martin’s JJ project.
You’ve been working on comparing Git reftable implementations with JGit alternatives. Could you walk us through what motivated this research and preview any interesting findings you’ve discovered?

Being the Gerrit Code Review release manager comes with many responsibilities, including verifying that whatever we release is production-ready and always better than what has ever been released. That also includes, first and foremost, the Git performance, following Shawn Pearce’s (Gerrit Code Review project founder, R.I.P.) mantra, “performance is a feature.”

We have been working in Q1 of 2025 to release and certify Gerrit v3.12, which includes the latest and greatest of JGit’s implementation of reftable, which was available since 2019 but not used in Gerrit because of the lack of support from the C Git project. Some parts of Gerrit use the “C Git” implementation for some scripting side and replication; therefore, a Git repository with reftable would not have been compatible with Gerrit until Git v2.45, which was released last year.

In February 2024, at the time of the release of reftable support in Git v2.45, I was busy with my AI research work for optimising Git performance, and I immediately thought that it was the right time to put JGit and C Git implementation of reftable in the arena and see how they interoperate and perform during heavy workload.

The first finding was that reftable has an entirely different philosophy from any other ref storage used before by Git. Loose refs and packed refs are both based on the concept of file-level locking and caching. Both C Git and JGit ensure that every update is atomic by carefully creating and releasing ref-level or packed-refs-level lock files and using atomic filesystem updates to ensure that the concurrency of reads and updates does not impact the normal functionality of in-flight operations. JGit has a “wait for lock” mechanism where the in-flight operation would wait for the lock file to be released before acquiring the resource, with an exponential backoff mechanism on packed-refs, whilst C Git just fails the operation with a lock failure.

Reftable is different because it is designed to be highly scalable and performant, compared to loose refs or packed-refs. To prioritise performance and low latency, reftable decides to give up thread safety and locking altogether, relying on an optimistic locking pattern. In a nutshell, whilst packed-refs blocks the file and waits until it is released, reftable allows multiple users to access the same data on disk and refer directly without locking. The operation is always safe because, unlike packed-refs and loose-refs, the reftable files are always immutable and therefore safe to be shared concurrently without any locks.

What’s the catch? The concurrent updates of the same refs by two different threads or processes will want to update the list of reftables simultaneously. Whoever manages to perform the update is gaining the “logical lock” and will cause any other concurrent threads or processes to fail the whole transaction they may have prepared.

Why is this different from loose-refs and packed-refs? The client interaction and compensation behaviour with a reftable needs to be substantially different: if with loose-refs or packed-refs the client was retrying the operation, or just waiting in case of JGit, with reftable the client should abort the whole logical operation, destroy the current snapshot of the reftable read in memory, and restart the whole transaction from scratch.

The issue here is that reftable is simply configured as a storage format for the refs, and the higher layers are currently unprepared to manage the difference in behaviour. This is currently causing trouble in the JGit world, with some initial issues reported at the API level, like the lack of “auto-refresh” and even more problematic stability problems reported on Gerrit Code Review when using reftable from concurrent threads.

The $1M question about reftable is, “Is it ready for mainstream use in production?” My answer is obviously a bold yes, but with a very important caveat: whoever is using reftable should be aware of what it is and how it should be used, and cannot be simply used blindly, assuming that it works exactly as a loose-ref or packed-refs. Reftable is ready, Git and Gerrit Code Review aren’t ready yet to leverage it, and I am sure they will soon be adjusted to get the best use of it.
What’s your approach to load testing Git repositories - which tools work best, what key metrics should organizations monitor, and what are some interesting findings from your research in this area?

At GerritForge, we’ve been investing a lot of time and effort in testing and improving the performance of Git repositories, as demonstrated by the recent research paper published on the use of AI to improve repository performance 100x times.

Over the years, we have developed much experience, successfully using the Gatling framework and extending it to support the Git protocol over HTTPS and SSH. The use of Gatling is great because it allows us to create very comprehensive scenarios using a DSL (domain-specific language), which is high-level and can replicate real-life user behaviour. Replicating real-life traffic is paramount when testing a Git repository performance because it allows creating future volumes in terms of length of delta-chains, number and distribution of refs, and number of packfiles / loose objects, that reflect the project lifecycle.

Another key aspect of generating a workload against a Git repository is scaling up the clients and making their requests parametric enough to avoid different requests locking each other. With Gatling, you have the concept of “user sessions” where different logical users can have dynamic variables used in the Git requests that can be used for making the operation independent (e.g., branch name fragments, or tags) and avoiding them from failing or ending up in a deadlock.

As part of our research work, I managed to recreate 10 years of Git traffic generated by hundreds of users and execute it in just 12 hours, thanks to Gatling and the Git-Gatling plugin.

An interesting finding from the research and experiments is that over 95% of the CPU time is spent in serving git-upload-pack commands (not really a surprise though), of which 90% of it is spent in the “search-for-reuse” phase.

A second interesting finding is that the presence of a bitmap, single or multi-pack, is not a guarantee of fast and effective Git operations: the quality of the bitmap also matters a lot. A bad bitmap could be so detrimental that removing it could make the Git repository much faster, which may sound counterintuitive.
Based on your testing, what improvements do you think are most needed in Git’s core implementation?

I believe that the Git GC process needs a full revamp: the way it is designed today isn’t suitable for large repositories. I have presented a simple “role play” demo of what could happen to a large mono-repo when you are trying to resolve a production slowdown running a Git GC: in my imaginary scenario, a large team of developers is pushing a lot of changes to get the latest features through on their product’s mono-repo, not unlike what happens when a large developer conference is approaching and company ABC wants to launch a new version of their product DEF. The operation raises the main metrics of the repository and makes the “search-for-reuse” phase explode, causing the complete blockage of the CI/CD pipeline. The Git SCM Manager knows what to do … and runs a Git GC, causing even more damage than the original problem.

I believe Git GC needs to be redesigned from the ground up. Instead of being a simple sequence of operations, it needs to be much more intelligent and adaptive to perform the right operation at the right time. This could also be “do nothing” as the CPU load is too high or the volatility of the repository is diverging.
How do you see the relationship between Git and JGit evolving in the future?

I believe Git and JGit have a wonderful symbiosis of ideas and code: many popular features in JGit ended up innovating and inspiring similar implementations in Git (e.g., bitmap, ref-table, just to name a couple). Also, the other way around is happening, with the implementation of MIDX in JGit recently merged, thanks to the collaboration of GerritForge and Google.

I like Git because it makes the language absolutely irrelevant to the implementation: extending Git doesn’t mean you have to write C code, and you can always start a brand new Git functionality in a language XYZ in the future. Git is all about data and protocol specification, not language, code, or operating system.

I believe that should remain the case, and I am looking forward to new languages implementing and innovating on Git, like the recent Gitoxide project, a pure-native implementation in Rust.
If you could get a team of expert developers to work full-time on something in Git for a full year, what would it be?

I may repeat myself, but I would redesign the Git GC command from the ground up.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Well, I would get rid of SHA-1 altogether immediately, forget about the legacy, and force everyone to use SHA-256 … but change requires time.
What is one of your most favourite features of Git?

I thank all the Git developers every single day for the interactive rebase. I use it as my bread and butter every morning.
What is your favorite Git-related tool/library, outside of Git itself?

I am shamelessly admitting that I love Git command line and I do not feel I need anything else as a tool or library to interact with it. Many people find it confusing, and I agree that some syntax could be misleading. Nevertheless, it is worth using it, proposing changes, and improving how it works and is perceived by the developers.

A tool that requires other tools is a symptom of a problem.
Could you brief a bit about one of your most memorable experience with Git?

As you haven’t mentioned if the experience should be positive or negative, I always mention the world-stage attention I got from force-pushing hundreds of Git repositories on the Jenkins CI organisation over 12 years ago. It was bad and good at the same time, because despite the panic caused in hundreds of Jenkins CI projects, it demonstrated that force pushing isn’t a destructive operation, and all the BLOBs were easily recovered, and the refs pointed again to the expected SHA1.

Also, my unfortunate mistake highlighted the resilience of the Git repository model, where there isn’t a “single source of truth” and GitHub’s repository is just “one of the peer repositories” around the globe. You can always recover from any type of damage with Git, at least from what I’ve seen in my 15 years of contributing and using it with real-life large-scale repositories and customers.
What is your advice for people who want to start using Git? Where and how should they start?

This could have been a valid question 15 years ago, when Git was still “quite recent” and not widely adopted yet. Nowadays, Git is taught at school and universities and has become the de facto standard of any Open-Source project around the globe. I was also pleasantly surprised to learn that my 10-year-old son was introduced to Git by his Computer Science teacher at primary school.
There’s a common conception that “Git is confusing”. What are your thoughts about the same?

I believe the most confusing part of Git is the working copy and the staging area. That’s the reason why JJ gets rid of it altogether and introduces the concept of “unnamed” commit. That’s genius from Martin Von Zweigbergk, if you think about it: you just stage files because you’d like to create a commit. So the stage is the “next commit you’re about to write”, therefore the unnamed commit.
If there’s one tip you would like to share with other users of Git, what would it be?

Never use an IDE to manage your Git repository and commits: always stay in control of what happens and learn something every day by using the Git command line.
If there’s one tip you would like to share with other Git developers, what would it be?

I am not currently contributing to C Git, so my tip would be more for JGit developers instead. I would love to see more end-to-end JGit features and protocols testing using tools like Gatling and the Git-Gatling plugin.
Anything else that you’d like to share with us?

In the future, I’d like to see Git become just one standard feature of each operating system: anyone should version a file on their system, regardless of whether that file is source code, a document, a video, or a drawing. Maybe it is not a random event that the father of Linux is also the creator of the Git version control system, isn’t it?

Thanks for allowing me to share my experience with Git and my history of being a JGit contributor and committer.

Other News

Various

The Git Merge 2025 speaker list and schedule have been announced. It will be held on September 29 - 30, 2025, in San Francisco, CA, USA.
[ANNOUNCE] Git v2.50.0 by Junio C Hamano on the Git mailing list.
Highlights from Git 2.50 by Taylor Blau on GitHub Blog.
Mentions improvements for multiple cruft packs, including git repack --combine-cruft-below-size (and improvements to its --max-cruft-size option), incremental multi-pack reachability bitmaps (highly experimental), the “ort” merge strategy replacing the “recursive” strategy entirely, various git cat-file improvements, git maintenance new tricks, and more.
What’s new in Git 2.50.0? by Justin Tobler on GitLab Blog.
Mentions the new git-diff-pairs(1) command which accepts “raw” formatted filepair info (from e.g. git diff-tree) as input on stdin to determine exactly which patches to output, batched reference updates with git-update-ref(1) and its new --batch-updates option (which allows the updates to proceed even when one or more reference updates fails), the new --filter option for git-cat-file(1), improved performance when generating bundles with git-bundle(1) (used by GitLab to generate repository backups and also as part of the bundle-URI mechanism), and better bundle URI unbundling.

Light reading

How to Install Gitea (with SQLite3 and HTTPS!) on a VPS by Bruno Brito on Tower Blog.
Reduce the load on GitLab Gitaly with bundle URI. Discover what the bundle URI Git feature is, how it is integrated into Gitaly, configuration best practices, and how GitLab users can benefit from it. GitLab Blog post writen by Olivier Campeau.
How we decreased GitLab repo backup times from 48 hours to 41 minutes by Karthik Nayak and Manuel Kraft on GitLab Blog. Describes how the GitLab team tracked a performance bottleneck in git bundle create to a 15-year-old Git function and fixed it.
Working with stacked branches in git (part 2) by Andrew Lock on his blog, .NET Escapades, continues where Working with stacked branches (mentioned in Git Rev News Edition #93) left off.
Git: please stop squash merging! and Git: the danger of squash merging submodules by Lucas Seiki Oshiro on his GitHub Pages-powered personal blog.
- The first of those blog posts mentions Squash commits considered harmful by Manuel Odendahl and Squash merges are evil by L. Holanda.
- See the Combining branches comic by Julia Evans (@b0rk) for an explanation about the differences between merge, rebase, and squash merge.
Cleaning up gone branches by Phil Haack on his You’ve Been Haacked blog. Describes how to delete all the branches that have been merged into the default branch, even if the project uses Squash and Merge when merging PRs (also known as squash merge).
Part 7: Office Migration from Source Depot to Git, or how I learned to love DevEx by Daniel Sada on his personal blog (part of his My career so far series).
- Nicely complements Microsoft’s Performance Contributions to Git in 2017 by Derrick Stolee on Microsoft Dev Blogs, mentioned in Git Rev News Edition #40, and other posts at https://stolee.dev/.
Git Branch Manager: a manager for git branches by Dave Schumaker on his blog, describes how he created the Git Branch Manager tool by “vibe coding” with Claude Code. The ‘P.S.’ part just kills it…
no more gitmojis on Sids’ blog; moving from gitmojis to just using conventional commits.
- Gitmoji was first mentioned in Git Rev News Edition #47, though then under a different URL (which now redirects to the current one).
- The similar Emoji-Log commit log messages standard was mentioned in Git Rev News Edition #101.
- The Conventional Commits specification was first mentioned in Git Rev News Edition #52, and in many editions since.
git diff --ignore-all-space makes code review way easier by Garrit Franke on Garrit’s Notes blog; a TIL (Today I’ve Learned) style post.
Per-project git commit templates by Tyler Cipriani on his blog. Mentions in passing different commit guidelines used by various projects, like Conventional Commits, Gitmoji, Problem/Solution format used by ZeroMQ, and Acked-by:, Cc:, and Co-developed-by: trailers used by Linux kernel developers.
The history of change-packing tools at Microsoft (so far) by Raymond Chen on Microsoft Dev Blogs: The Old New Thing (2018).
Change-packing is a way to save a whole changeset or commit to a single file, to be able to save changes without committing them (like git stash), or to get another developer’s opinion on code you’ve written (buddy build), etc.
GIF: The Git Interchange Format by Will Richardson on his blog, about how to cram a whole git repo (with history) into an animated GIF.

Scientific papers

Shane McIntosh, Luca Milanesio, Antonio Barone, Jacek Centkowski, Marcin Czech, Fabio Ponciroli: “Using Reinforcement Learning to Sustain the Performance of Version Control Repositories”, ICSE 2025: 47th International Conference on Software Engineering, https://rebels.cs.uwaterloo.ca/papers/icse2025nier_mcintosh.pdf (preprint).
Jakub Narębski, Mikołaj Fejzer, Krzysztof Stencel, Piotr Przymus: “PatchScope - A Modular Tool for Annotating and Analyzing Contributions”, ISSTA 2025: 34th ACM SIGSOFT International Symposium on Software Testing and Analysis, DOI:10.1145/3713081.3731727 (short paper, free access).
- PatchScope was first mentioned in Git Rev News Edition #117.

Git tools and sites

GetHooky is a simple git hook manager for everyone. Inspired by Husky, but a CLI tool, thus works for every stack. Written in Go, under MIT license.
- Husky, a Git hook management tool, was first mentioned in Git Rev News Edition #63; you can find links to other articles talking about it in #87, #89, and #102.
Git Branch Manager is a terminal-based (TUI) Git branch management tool that provides an interactive interface for managing Git branches, with rich visual feedback and advanced features. Written in Python (with the help of Claude Code), under MIT license.
Gittyup is a graphical Git client designed to help you understand and manage your source code history. Written in C++ using Qt, under MIT license. It is a continuation of the GitAhead client, mentioned in Git Rev News Edition #59.
Conventional Changelog is an npm tool to generate changelogs and release notes from a project’s commit messages and metadata. Written in TypeScript and JavaScript, under ISC license. First mentioned in Git Rev News Edition #81.

Releases

Git 2.50.0, 2.50.0-rc2, 2.50.0-rc1
Git for Windows 2.50.0.windows.1, 2.50.0-rc2.windows.1 (pre-release), 2.50.0-rc1.windows.1 (pre-release), 2.50.0-rc0.windows.1 (pre-release)
libgit2 1.9.1
GitLab 18.1.1, 18.0.3, 17.11.5, 18.1, 18.0.2, 17.11.4, 17.10.8
GitHub Enterprise 3.17.1, 3.16.4, 3.15.8, 3.14.13, 3.13.16, 3.17.0
GitKraken 11.2.0, 11.1.1, 11.1.0, 11.0.0
GitHub Desktop 3.5.0, 3.4.21
GitButler 0.14.35, 0.14.34
Tower for Mac 13 - Release Blog Post / YouTube video
Tower for Windows 9.1 (Beta) - Release Blog Post

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Luca Milanesio, Bruno Brito, Lee Reilly and Štěpán Němec.

Git Rev News Edition 123 (May 31st, 2025)

chriscool — Sat, 31 May 2025 11:06:51 +0000

Git Rev News: Edition 123 (May 31st, 2025)

Welcome to the 123rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of April and May 2025.

Discussions

General

[GSoC] Welcoming our 2025 contributors and thanking our applicants

The Git project was accepted in the Google Summer of Code (GSoC) this year again, and 3 applicants were selected:
- Meet Soni will work on the “Consolidate ref-related functionality into git-refs” project mentored by Patrick Steinhardt and Jialuo She. See Meet’s blog and repository for more.
- Lucas Seiki Oshiro will work on the “Machine-Readable Repository Information Query Tool” project mentored by Karthik Nayak and Patrick Steinhardt. See Lucas’s blog and repository for more.
- Ayush Chandekar will work on the “Refactoring in order to reduce Git’s global state” project mentored by Christian Couder and Ghanshyam Thakkar. See Ayush’s blog and repository for more.

Reviews

[PATCH] git: add --no-hooks global option

Derrick Stolee, who prefers to be called just Stolee, sent a patch to the mailing list that added a new --no-hooks global option and an equivalent GIT_HOOKS environment variable to Git. The goal was to allow users to disable all Git hooks during command execution.

This could be useful for expert users who would want to bypass pre-commit hooks when they have poor performance or perform useless checks.

Switching between enabled and disabled hooks and other workarounds, like setting core.hooksPath to a “bogus path”, did not look convenient and very safe.

brian m. carlson, who spell their name using only lowercase letters, replied to Stolee acknowledging the need for this functionality as some Jenkins users already set core.hooksPath to /dev/null for security reasons. They warned that disabling hooks could break Git LFS in a way that is “less noticeable and detectable” than the current /dev/null approach.

They agreed that certain hooks like pre-commit hooks should be optional, for example to make it easy to commit some work-in-progress that doesn’t meet standards, but saw fewer reasons to bypass hooks that could be important for repository integrity.

Stolee agreed that some hooks are important for integrity, but said his intention was on the side of optional hooks.

Phillip Wood also replied to Stolee’s initial email noting that there is already git commit --no-verify which bypasses the pre-commit and commit-msg hooks. He argued that hooks so slow that users want to bypass them are self-defeating and that the solution should be to fix the hook’s performance rather than make it easier to skip. About setting core.hooksPath to /dev/null, he asked why it could be unsafe. In general he said he wasn’t convinced that --no-hooks was a good idea, and later asked for “a clearer motivation” to better understand its usefulness.

Stolee agreed that setting core.hooksPath to /dev/null was safe, and said he had forgotten that could be used instead of a bogus path.

Junio Hamano, the Git maintainer, then replied to Phillip thanking him for pushing back on the idea, and saying that there should be a “compelling reason” to justify a change.

Also instead of implementing options to disable hooks or configuration in some user facing “porcelain” commands, Junio advocated for cleaning up and refactoring these commands into new stable “plumbing” commands designed to be easily used in scripts.

In the meantime, Lucas Seiki Oshiro replied to Phillip. Lucas had noticed that using /dev/null to disable hooks wasn’t mentioned in the documentation of core.hooksPath, even though it was tested in a test script. He asked if Stolee’s patch should therefore be turned into a documentation patch.

brian agreed with Lucas that documenting how to disable hooks was a good idea even if the --no-hooks option wasn’t implemented.

D. Ben Knoble also replied to Stolee’s initial patch. He supported the addition of the --no-hooks option, sharing his own frustrations with poorly performing or difficult-to-manage hooks. He described how a tool re-enables hooks after every npm install leading him to overuse --no-verify, which he considered a worse situation. He believed there should be a safe and sane way to disable optional client-side hooks and felt that a --no-hooks option would be useful, potentially encouraging better practices like moving certain checks to server-side hooks.

Stolee then replied to Junio thanking him for deciding about this and saying he would follow up with a version 2 of his patch that would only document that setting core.hooksPath to /dev/null was the supported mechanism to disable hooks.

In the version 2 of his patch, Stolee just updated the documentation of the core.hooksPath configuration option, adding the following small paragraph:

You can also disable all hooks entirely by setting core.hooksPath to /dev/null. This is usually only advisable for expert users and on a per-command basis using configuration parameters of the form git -c core.hooksPath=/dev/null ....

Lucas replied to that new patch. He suggested rewording the documentation to focus on non-expert users rather than experts. Stolee disagreed, explaining he intentionally targeted expert users as a “there be dragons here” warning about the risks of disabling hooks.

brian supported Stolee’s approach, agreeing that this feature should be presented as expert-only due to the potential for data loss (like missing Git LFS uploads). He appreciated Stolee’s gracious pivot from code changes to documentation.

Junio also thanked Stolee for gracefully changing direction and ensuring no loose ends were left after abandoning the original approach.

Other News

Light reading

What I’ve learned from jj (Jujutsu) by Nathan Witmer on zerowidth positive lookahead blog.
Jujutsu (jj) is an experimental Git-compatible DVCS, first mentioned in Git Rev News Edition #85.
Git aliases by Heitor de Bittencourt on Heitor’s Log blog, which includes comparison with shell aliases, and is only missing the trick to set git completion for the ! alias.
Pushing a whole stack of branches with a single Git command (with the help of git aliases) by Andrew Lock on .NET Escapades.
Tally All Git Trailers in a Repository, with a list of interesting and useful trailers (with many links), by Caleb Hearth on his blog.
You can use Git to version control your notes, and here’s how I do it by Ayush Pande on XDA Developers (with Joplin as an example of a note-taking application one can use with Git).
A Short Guide on Git for Vibe Coders by Anfal Mushtaq on his blog.
Version Control To The Max by Al Williams on Hackaday, about backing up the entire development environment (with QEMU or VirtualBox or VMWare).
Converting a Git repo from tabs to spaces with the help of the “filter” gitattribute and the expand tool (part of the coreutils), by Eevee on Fuzzy Notepad blog (2016).
How the GitHub CLI can now enable triangular workflows by Tyler McGoffin on GitHub Blog.
Using git-upload-pack for a simpler CI integration, on how Screenshotbot can now extract commit graph data from remote repositories (assuming one has SSH access to their Git repositories), by Arnold Noronha on Screenshotbot Blog.
Fixing SSH Conflicts: Using a Separate SSH Key for GitHub by Hastycode Andreh on DEV.to. One trick to add is the possible use of url.<base>.insteadOf.
The reductionist theory or rethinking of .gitignore bloat by Arturs Jansons on DEV.to. Mentions gitignore.io, first mentioned in passing in Git Rev News Edition #6, then linked to (with new final URL) in Git Rev News Edition #94, and github/gitignore - which was first mentioned in passing in Git Rev News Edition #21, then also linked to in Edition #94,

Git tools and sites

A modern theme for cgit by Lee Yingtong Li on Inane Observations blog. The source code for this themed fork of cgit is available at https://yingtongli.me/git/cgit-yli-theme. Under GPL v2 license.
AutoGit-o-Matic is a Bash script that automates Git operations across multiple repositories. It helps you pull or fetch updates from multiple repositories with a single command (with dry-run capability), scans directories for Git repositories automatically, logs operations in both TXT and JSON formats, and is configurable via an INI file. Under GPL-3.0 license.
StatsCat is a CLI tool to get per-author and per-directory statistics of all your Git repositories. Written in Go, under MIT license.

Releases

Git 2.50.0-rc0
GitLab 18.0.1, 17.11.3, 17.10.7, 18.0, 17.11.2, 17.10.6, 17.9.8
Gerrit Code Review 3.10.6, 3.11.3, 3.12.0-rc5, 3.12.0-rc6, 3.12.0, 3.9.11
GitHub Enterprise 3.16.3, 3.15.7, 3.14.12, 3.13.15, 3.17.0
GitKraken 11.1.1, 11.1.0, 11.0.0
GitHub Desktop 3.4.20
Garden 2.2.0
Git Cola 4.13.0
GitButler 0.14.26, 0.14.25
git-credential-oauth 0.15.1

Credits

Git Rev News Edition 122 (April 30th, 2025)

chriscool — Wed, 30 Apr 2025 11:06:51 +0000

Git Rev News: Edition 122 (April 30th, 2025)

Welcome to the 122nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of March and April 2025.

Discussions

General

Let’s celebrate Git’s 20th anniversary this coming Monday!

Johannes Schindelin (alias Dscho) posted on the mailing list that the oldest Git commit was performed on April 7th, 2005. So Monday April 7th, 2025 was the 20th anniversary of Git!

To celebrate this event, Dscho created a channel on Git’s Discord, called #20th-anniversary where everyone is welcome, especially to talk about their encounter with Git.
[ANNOUNCE] Git Merge 2025, September 29-30, San Francisco, CA

Taylor Blau announced a new Git Merge 2025 conference on September 29-30 at GitHub HQ in San Francisco along with a Contributor’s Summit on September 30.

Registration and a Call for Proposals, which closes on May 13th, are open. Requests for financial assistance with travel costs can be sent to the Git PLC at git@sfconservancy.org.
Patch (apply) vs. Pull

To celebrate Git’s 20th anniversary in our own way let’s talk about a discussion on the Git mailing list that happened nearly 20 years ago.

On June 20, 2005, Darrin Thompson sent an email about a discrepancy he was perceiving between his mental model of how Git worked and a common practice he observed on mailing lists.

He understood that on one hand Git was about people duplicating locally the remote history they were interested in, which provided common points in history that enabled “intelligent merging”, while on the other hand mailing lists were filled with emailed patches.

He asked how the patches were created and handled to ensure they could be properly dealt with by the receivers and those who would later pull from those initial receivers.

He was basically trying to reconcile the patch-based workflow on mailing lists with Git’s design, especially its merging philosophy based on a common history.

Junio Hamano, who would later become the Git maintainer, then replied to Darrin acknowledging that emailed patches were essentially “out of band” communications. Merges could still work if the same patch had been applied independently. Even if that wasn’t ideal, it was “manageable”.

Junio then described his workflow, which consisted of regularly pulling from Linus, discarding his HEAD, using Linus’ HEAD instead, and reapplying onto it some patches that Linus had rejected but he still considered good. Then he would work on new changes and commit them on top.

Darrin, questioning this approach, asked for ways to manage patches as a series of commits, and wondered if that would still allow cherry-picking patches.

Then Daniel Barkalow and Catalin Marinas chimed in to talk about StGit (Stacked Git) which helps manage Git commits as a stack of patches. Catalin Marinas was the creator of StGit, which seems to still be developed these days as there was a 2.5.0 release in January 2025.

Daniel suggested integrating functionality similar to StGit into Git to help with applying patches and bridging the gap between the patch-based workflow and Git’s commit-based model in general, even though he thought that commits were “fundamentally resistant to cherry-picking”.

Catalin over the course of the discussion provided specific details about how StGit could address Junio’s workflow. For example, StGit would automatically detect when a patch was already merged upstream and warn the user. It could also handle conflicts during the reapplication process using diff3.

Catalin also mentioned that StGit would soon support pulling changes from a remote tree along with patch series information, making it easier to apply patches from different branches.

Meanwhile, Linus also replied to the email where Junio described his workflow, proposing “a different kind of merge logic” to automate some of the steps, as individual developers often want to move their work forward to the current tip, instead of merging it. The new script would “try to re-base all the local commits from the common parent onwards on top of the new remote head”.

Linus showed some steps that the script would perform, some of them using a new git-cherry-pick script that “basically takes an old commit ID, and tries to re-apply it as a patch (with author data and commit messages, of course) on top of the current head”.

Then Linus, Junio and Daniel discussed how to implement this. One problem appeared to be how to automatically detect patches that had already been merged even where there were small changes, like typo fixes or whitespace changes, in the patches.

Daniel suggested that authors could give an ID that would be preserved across various later modifications to each of their patches. Linus didn’t like this idea because he thought that they could be useful for specific projects but should be tracked outside of Git. Inside Git, he thought they could create confusion as it wouldn’t be clear if a patch has been modified or not.

Daniel then asked Linus if he actually modified patches before applying them. Linus replied that he very often did modify them and that he absolutely didn’t want to apply them first and then modify them as he didn’t want “crap” in his code. He further elaborated that his git-apply tool was strict and refused to apply patches with any ‘fuzz’ (mismatched context lines), only allowing patches that matched exactly, potentially after adjusting for line number offsets. He said:

“So I want things to be cleaned up before they hit the tree, rather than have a really dirty history. A dirty history just makes it harder to read, and I don’t believe in a second that it’s ‘closer to reality’ like some people claim.”

“I don’t believe anybody wants to see the ‘true’ history. If they did, we’d be logging keystrokes, and sending all of that around. Nope, people want (and need, in order to be able to follow it) an ‘idealized’ history.”

Martin Langhoff also contributed to the discussion, noting that rebasing and replaying local history was an approach he had used successfully with Arch. He suggested that the rebasing process should be restartable after encountering a failed cherry-pick, and proposed adding features like a “skip list” for patches already merged upstream and a --stop-at option to handle batches of commits incrementally.

Daniel and Linus continued to discuss practical ways to identify and manage patches across repositories. Linus proposed hashing the actual changes in a patch, ignoring line numbers and whitespace, rather than relying on explicit IDs or commit metadata. He implemented this idea in the form of a git-patch-id and tested it on the Linux kernel repository where it found 15 duplicate patches in the kernel history and processed around 2788 patches in under a minute with no false positives.

Junio replied with a series of three patches to the email where Linus had suggested some steps that the script to re-base all the local commits would perform. The cover letter of his series was named “Rebasing for ‘individual developer’ usage”.

The first patch added a -m flag to the git-commit-script which allowed committing using the commit message and author information from an existing commit.

The second patch implemented a new git-cherry script to find commits that are in the current branch but not in another branch, so it can help find commits that haven’t been merged upstream.

The third patch implemented a new git-rebase-script that used the functionality from the two previous patches to actually implement rebasing.

Community interview

Editor note: For Git’s 20th anniversary, we are doing an exclusive collaborative community interview and curating answers of various community members. Also, there’s a short Q&A with our zealous, inclusive and tireless maintainer that follows below.

What’s your favorite Git trick or workflow that you wish more people knew about?

Thalia Rose: For rebase-heavy workflows, git range-diff is incredibly useful. To compare against upstream, use git range-diff @{u}...@, and to compare against the previous HEAD, use git range-diff @{1}...@.

Lucas Seiki Oshiro: Everything related to code archaeology (git grep, git log -S/-G, git log -L and git bisect). Those are my primary debugging tools and every time I explained them to other people they find them mind-blowing and useful. And they also started loving it :-)

Elijah Newren: range-diff. The ideas behind it ought to be the basis for code review, IMO. Commits should be the unit of review (including commit messages as a fundamental and primary thing to be reviewed), and a series of commits should be the unit of merging. I dislike most code review tools, because they get one or both of those things wrong. Getting both of those things right naturally leads to range-diff or something like it being a very important part of the workflow, at a minimum for detecting which commits in a series are unmodified and which have been updated and need to be further reviewed.
What was your worst Git disaster, and how did you recover from it?

Thalia Rose: When I was first starting with Git, I wanted to make a repo to preserve my first coding project when I was twelve, a bunch of VBS scripts. I had assumed that Git maintained file modification timestamps, so I deleted the originals because they were now redundant. I now no longer know exactly when I wrote them and have been careful about timestamps ever since.

Luca Milanesio: I suspect to be one of the worst offenders :-) [ ref ]

Thankfully I was using Gerrit Code Review and the replication plugin: the refs were not lost but just rewind and we could reset all the correct SHA1s for all of them.

Lucas Seiki Oshiro: I don’t remember something that I did, but I remember a simple and curious disaster: our deploy workflows stopped working, only leaving a message like “cannot fetch ambiguous reference master”. I decided to investigate what happened and I found out that someone by mistake (I don’t know how) created a tag called master and pushed it to GitHub. By the time we used the master branch for deploy, and the workflows didn’t know if they should use the master branch or tag. GitHub didn’t have a feature for deleting tags through the web interface, so we thought “what should we do?”.

The solution was to run git push origin :refs/tags/master. Simple, but not obvious. A classic case where it only required a screw to be turned, but all the hard work was to find which screw should be turned.

Elijah Newren: My worst Git-related disaster wasn’t with Git directly but with our Git hosting software we used at a prior job, Gerrit. ‘twas a “startup” that was still forming good practices. We had both a production and a staging instance. The staging instance was seeded with a copy of production data so we could do scale testing…but that seeding process was a multi-step manual thing; it hadn’t been automated. One step was, as best I recall, “drop database gerrit”, followed by loading the production copy of the mysql database (this was long before NoteDB arrived). And as many readers probably have guessed by now, I was on the wrong host one day when I ran that command.

The actual git repositories were still intact, but the review metadata was toast. Luckily, we had a backup from about 7 hours earlier, so we could recover the older review metadata and with some hackery fix the mysql metadata mismatch with the newer repository contents. And since Gerrit emailed folks comments from reviews as they were posted, we could tell people to look at their emails for the pieces we couldn’t recover.

It was a really long night trying to fix things. Some folks told me they thought I was going to throw up just looking at me. But I learned how wonderful it was to be at a company with blameless post-mortems, and I appreciated the many folks who reached out to tell me stories of mistakes they had made. They were more interested in whether we learned our lesson and put processes into place to prevent repeats, and I definitely did both.

I did, of course, also get some good-natured ribbing, such as people saying I got to play the part of little Bobby Tables once (see this xkcd comic if you don’t know that reference). I kindly reminded them that I didn’t drop a table – I dropped the whole database (plus, it wasn’t injection, it was just running a command in the wrong location). Also, one of my colleagues helpfully modified the prompt on production to be red and bold, “This is PROD Gerrit”, and the prompt on staging to be green, “This is staging Gerrit; it’s okay to drop database here!” The prompts ended up not mattering since I automated the process, and made sure the process just error’ed out if run on prod instead of staging. But the prompt persisted for many years anyway, because I thought it was a hilarious way to poke fun at my blunder.
If you could go back in time and change one design decision in Git, what would it be?

Luca Milanesio: Use SHA-256 straight away, as it was published 24 years ago and already existed at the time Git was designed.

Lucas Seiki Oshiro: Perhaps writing a more abstract CLI. After studying Git a little more deeper it makes sense for me, but I would group the functionality into more high-level subcommands and would make the flags and options more consistent across the subcommands.

For example, Docker CLI have all the image operations under docker image and all the network operations under docker network. If I want to delete an image, I use docker image rm, if I want to delete a network, I use docker network rm, and so on. I would make Git CLI work based on that idea, for example:
- git branch add my_branch
- git branch delete my_branch
- git branch list
- git remote add my_remote ...
- git remote delete my_remote
- git remote list
- git tag add my_tag
- git tag delete my_tag
- git tag list
With some shorter alias, just like Docker has docker rmi and docker rm.

Elijah Newren: The index. For a few reasons.
1. Performance.
  1. The index is pervasive throughout the codebase, and while it works great for small repositories, it means that many operations are O(size of repository) instead of O(size of changes). sparse indices help, but the code has to be carefully audited for sparse indices to work with each codepath, and even then there tends to be a fallback of just-load-everything-anyway because the data structure doesn’t lend nicely to just expanding a little more.
  2. An under-appreciated aspect of the performance improvements that came from our new merge strategy, merge-ort, were due to dispensing with the index as the primary data structure. The index had two problems:
    1. first of all it meant loading every path in the repository, which would have prevented ort’s optimization to avoid recursing into subtrees when unnecessary (an optimization that often made merges e.g. 50x faster). Sparse indices didn’t exist back then, but even if they had we would have had to complicate them significantly in order to have their sparseness be determined by renames and the intersection of modified paths on the two sides of history instead of having sparseness determined by user-defined path rules; I think that’d have been much more complicated than just dispensing with the index as the data structure, but we didn’t even have sparse indices back then anyway.
    2. Second, the use of the index as done in the old merge strategy, merge-recursive, resulted in O(N^2) behavior since entries (including conflicted higher order stages) had to be inserted in sorted order. Deleting entries didn’t have the same O(N^2) problem due to some tricks to queue the deletion for later, but attempting to do the same for insertions was far from straightforward and I believe would have required making some other data structure primary and then forming the index at the end. (Note that the primary data structure used, whatever it is, cannot just have a list of things to insert, it also needs to be checked for various properties intermingled with insertions…and those sometimes relied on the fact that the index was sorted for quick lookups.)
      
      (Note that a tree-structured index rather than a linear index would resolve these problems. But retrofitting the entire codebase is probably never going to happen…)
2. Cognitive Complexity.
  The funny thing is, although I say this, I use the index all the time. I use git add -p a lot. I very much need to slice and dice my changes into different commits, and tend to have dirty changes that I don’t want pushed.
  
  But slicing and dicing before things are committed, as opposed to being able to slice and dice after, is a choice that adds a lot of complexity to the user interface and does so even for users who aren’t interested in slicing and dicing commits. We don’t have a sufficiently flexible set of tooling for slicing and dicing commits after-the-fact within git to switch to a post-commit-slice-and-dice workflow even today, but I suspect that some of the ideas from JJ would or could be much better than the methods I use today in git to slice and dice commits.
Which Git feature or improvement over the past 20 years do you think had the biggest impact on your workflow?

Lucas Seiki Oshiro: Sorry, but I can’t answer. I am from a generation that started programming when Git was already the de facto VCS so I can’t compare a world that has it with a world that doesn’t have.

Elijah Newren: Speed.

Being able to instantly switch branches (in smaller repos, sure, but CVS and SVN couldn’t pull it off even in small repos) was a game changer.
What Git problem that existed 10 years ago has been most successfully solved?

Lucas Seiki Oshiro: Sorry again, but 10 years ago I was only starting to use Git and when I started to use more complex features they already were there.

Elijah Newren: Merging and rebasing with lots of renames (and generally merging without a worktree or index). I’m obviously a bit biased on this point, but that doesn’t mean I’m wrong. ;-) It used to be awful and works great now.

Relatedly, merging without a worktree or index was problematic; you had to either use an alternative merge strategy with limited capabilities, or use something other than git (e.g. libgit2). But now git handles it well with its default merge strategy.
Which Git commands or workflows do you think are still misunderstood or underutilized today?

Lucas Seiki Oshiro: I think squash merges and submodules are really misunderstood, yet they are the opposite of being underutilized. Sadly I saw several people using them in daily basis, based on the wrong idea of what they are and then using them incorrectly.

What I think is underutilized is the full power of commits being a good source of documentation and good resource for, again, performing code archaeology that may help understanding what the code does and debugging it. Several developers treat the commits as just checkpoints.

Elijah Newren: range-diff is very under-utilized, but I already discussed that above.
What’s one Git based project, tool, or extension you think deserves more recognition from the community?

Lucas Seiki Oshiro: Perhaps it would be better to leave this question for other less known tools. But if you want an answer, I think:
- Delta is a really cool tool for formatting the diff-related outputs;
- Kworkflow is a powerful tool for contributing to the Linux kernel source code (I should also try it for contributing to the Git source code);
- Merge drivers in general. diff3 works in most cases but it is only based on pure diffs, without performing deeper operations based on the file format they are merging.
What Git feature or capability surprised you most when you first discovered it?

Lucas Seiki Oshiro: As you may have noticed, I’m really a fan of Git archaeology :-), so I would say all that I mentioned in the first answer (i.e., git grep, git log -S/-G, git log -L and git bisect). But my favorite is still bisect. It’s an egg of Columbus and everyone that I have shown it to was equally amazed by it!
What’s your boldest prediction about how version control might look in another 20 years?

Lucas Seiki Oshiro: I still see Git as the dominant VCS in the future, but I think more Git-based VCSs (like Jujutsu will arise. Just like we have today programming languages built on top of the stack of the other languages (e.g. Clojure, Kotlin and Scala on JVM, TypeScript on JS), networking protocols written on top of other protocols (e.g. QUIC on UDP, gRPC on HTTP) and so on.

The Git core is simple, flexible, transparent and powerful and there’s still room for people using it directly in several creative ways. Once I saw a project using it as a backend for a NoSQL database, who knows how many use cases we still have for it.

Elijah Newren: I’m more interested in what storms might be brewing along that path, and what we might be able to do to avoid them. In particular, some questions and observations in that area:
- With monorepos growing ever larger, do we have hard-to-workaround-or-fix design decisions that pose scaling challenges? e.g.
  - the index data structure
  - per-directory .gitignore files, per-directory .gitattribute files, etc.
- …or do the prominent Git forges have hard-to-workaround-or-fix design decisions that’ll give Git a reputation for not scaling? e.g.
  - making refs/pull/NNN/merge a public ref and excessively implicitly updating it
- Will we face a crisis of interest? e.g.
  - git is currently written in C. Even if that’s not a liability already, coupled with “decades” I think it is. Young developers probably don’t want to learn C, and older ones who already know C may worry about C becoming a Fortran or Cobol.
  - Companies employing Git developers think “git already won” and redeploy those engineers on other problems
- Will the combination of issues above result in folks who want improvements deciding their best bet is not improving Git but in creating/funding an alternative? Will that snowball?
To me, the entry of new projects like JJ and sapling suggest the above are real concerns already rather than just theoretical. Both projects have compelling things that git lacks. I like the friendly competition, and the JJ and sapling developers are awesome to talk to at Git Merge conferences. But there is a risk that this friendly competition mirrors that of Git and Mercurial from years past, and that Git at some future point down the road ends up on the other side of that history and gets largely displaced by the alternatives. I’d rather not see that happen, but I sometimes wonder if we’re taking enough measures to avoid marching towards such an outcome.

Short Q&A with our maintainer, Junio C Hamano

Looking back over ~20 years of maintaining Git, what has been the most surprising or unexpected evolution in the project — technically or community-wise?

Technically, one of the things I found surprising is how many lines from Linus’s original version still survive in today’s codebase. The initial version of Git was 1244 lines spread across 11 files, which is miniscule compared to 300+ thousands of lines in 4600+ files in v2.49.0, but it is not fair to say Linus’s original genius is less than 0.3% of what we have. If you try running git blame in reverse, you’ll see that about 10% of lines we have in our tree came from the original version Linus released 20 years ago. You can check out a little script called “Linus” out of my “todo” branch and run it to see for yourself.

Community-wise, there weren’t many things that surprised me. I expected a bit more developers who are interested in the core part of system to stick around, say for more than 10 years, and I hoped that some of them would be from younger generations who have never seen any version control system other than Git, but how many among the active contributors we see on the list every week fall into that category? We have long-timers who are respected in the community, but we want to grow that pool by say 5 every year or so, some of them ready to stick around for another 10 years. In a recent interview, Linus said he wanted somebody with good taste who sticks around, and I do believe it is essential to have a sufficient number of long-timers who can guide new folks into the community.

So that is a bit of surprise that makes me a little sad, but at the same time, I think what is happening is that a development community of an extremely popular and successful system that is mature with friendly atmosphere has attracted many aspiring new folks, they scratch their own itches and have fun, but then they find more interesting things to do and go back to be happy end-users, which is totally expected and natural thing.
What are your thoughts about AI-assisted development tools in the context of Git? Do you see a place for Git itself to become more “intelligent”?

I’ve kept saying that https://lore.kernel.org/git/Pine.LNX.4.58.0504150753440.7211@ppc970.osdl.org/ is one of the most important design discussion in the early days of Git. In that article, Linus outlines how his “ideal” SCM tool would let you follow the history of a single function in today’s codebase backwards, notice that at certain revision the function appeared, but the tool finds five functions disappeared in the same revision, all looking very similar to the function we are interested in that was added there, and the tool can explain that the commit consolidated duplicated reimplementations done in various subdirectories into a single common function and adjusted the existing callers of them to the SCM user (if you want to learn more details, go to the original and read it twice, I’ll wait).

We can do git log -S<the-body-of-that-function> repeatedly to drill down the history to find the revision that introduced that new (possibly consolidated) function. In fact, the -S<pickaxe> feature was invented exactly for the purpose of serving as the first step of Linus’s “ideal” SCM tool described in the article. But “finding similar existing (and possibly getting lost) code in the same or possibly nearby revisions” have been nebulous. I do not think anybody in the Git circle tried it yet. I wonder, after 20 years, perhaps we can feed a project’s codebase to LLMs and let them figure out such a fact?
What’s your boldest prediction about how version control might look in another 20 years?

I do not even foresee what software development in 20 years would look like. I am not an insight kind of person.
What advice would you give to someone who might one day step into your role as Git maintainer?

Be original. I didn’t aim to duplicate the style Linus ran his tree during the first four months of the project. My successor does not have to duplicate my style of running the project, either. Having said that, personally I would like to see more distribution of responsibility. The maintainer may play a role of the final arbiter, but it would be great if we can come up with a mechanism to allow list participants to bear more of the burden of picking and choosing good direction to go, deciding if a particular change is worth doing or are there better ways to do the same thing, etc. I’ve been trying to nudge the list discussions in that direction for the past few years, but without much success, I think.

Other News

Various

Git turns 20: A Q&A with Linus Torvalds by Taylor Blau on GitHub blog.
Celebrating Git’s 20th anniversary with creator Linus Torvalds by Patrick Steinhardt on GitLab blog.
Linus Torvalds built Git in 10 days - and never imagined it would last 20 years by Steven Vaughan-Nichols on ZDNet.
20 years of Git. Still weird, still wonderful. by Scott Chacon on Butler’s Log (GitButler).
Journey through Git’s 20-year history by Patrick Steinhardt on GitLab blog.
GitHub MCP Server is now available in public preview. Model Context Protocol (MCP) is an AI tool calling standard that gives LLMs (Large Language Models) a standardized way to call functions, look up data, and interact with the world.

Light reading

Verifying tricky git rebases with git range-diff by Andrew Lock on his .NET Escapades blog.
Mirroring my git repositories using cgit for the interface and nginx as a web server. By Julien (jvoisin) Voisin on their blog.
Mirroring my Repositories from GitHub to GitLab, including both public and private repositories on GitLab Free tier. By Christian Cleberg on his blog.
Documentation as Code with AsciiDoctor, GitLab CI, and GitLab Pages by Jens Knipper on his personal blog.
Afraid to Git: a rant by Michiel Scholten on his dammIT blog, explaining how misbehaving AI scrapers cause him not to put his Gitea instance (his Git server) on the Internet, and force others - like Linux’ kernel.org - to use tools like Anubis.
Fedora change aims for 99% package reproducibility by Joe Brockmeier on LWN.net.
How to Exclude Commits from Git Blame by Bruno Brito on Tower’s blog.

Easy watching

Two decades of Git: A conversation with creator Linus Torvalds video interview (YouTube, 41:49).

Git tools and sites

Devlands is the game that creates immersive experience to help learning Git. Created by Jacob Stopak, the author of the Git-Sim tool to visualize Git commands directly in your own repo, which was first mentioned in Git Rev News Edition #95. Described in I struggled with Git, so I’m making a game to spare others the pain article on Initial Commit Blog.
Git Game Show is a text interface app that transforms your project’s Git commit history into a live, multiplayer trivia game. One user hosts a session, other players join remotely, and the system rotates through rounds of different question-based “mini-games,” awarding points and declaring a final winner.
dgit is a tool that allows you to treat the Debian archive as if it was a Git repository. Conversely, it allows Debian to publish the source of its packages as Git branches, in a format which is directly useable by ordinary people.
- Note that GitHub’s Spokes system that stores multiple distributed copies of Git repositories was once called DGit. See the Stretching Spokes article by Michael Haggerty on GitHub Blog mentioned in Git Rev News Edition #14.
Mega is an unofficial open source implementation of Google Piper (a proprietary, massive, centralized version control system that Google uses internally to manage their vast codebase). It is a monorepo & monolithic codebase management system that supports Git. More information can be found in Why Google Stores Billions of Lines of Code in a Single Repository. Written in Rust and TypeScript.
Oshit aka Oshiro’s git: VCS written in Haskell that tries to be compatible with Git. This is not safe to use, and is only meant for learning how Git works and how hard it is.
codeowner-filter is a simple web tool that solves the problem of finding just the files your team owns based on the contents of CODEOWNERS file. It will generate search filters for VSCode, scope configuration for IDEA IDEs, and a list.
CodeOwners Filter is a Visual Studio Code extension that gives you a visual representation of the CODEOWNERS file and helps you generate glob include patterns for any code owner.
rebuilderd is a tool that monitors the package repository of a Linux distribution and uses rebuilder backends like archlinux-repro to verify the provided binary packages can be reproduced from the given source code. Written in Rust, under GPL license.
reproduce is an open-source tool designed to independently verify whether a published npm package can be faithfully rebuilt from its declared source. It is described in the Reproducibility vs. Provenance: Trusting the JavaScript Supply Chain blog post by Darcy Clarke.
Graft is an open-source transactional storage engine designed for efficient data synchronization at the edge. It is described in the Stop syncing everything article by Carl Sverre, his Storing small things in big places Vancouver Systems talk (video on YouTube, 55:04), and his Building a serverless database replica with Carl Sverre High Performance SQLite talk (video on YouTube, 1:10:19). Written in Rust.

Releases

GitHub Enterprise 3.16.2, 3.15.6, 3.14.11, 3.13.14
GitLab 17.11.1, 17.10.5, 17.9.7, 17.11, 17.10.4, 17.9.6, 17.8.7, 17.10.3, 17.9.5
Gerrit Code Review 3.12.0-rc0, 3.12.0-rc1, 3.12.0-rc2, 3.12.0-rc3, 3.12.0-rc4
GitHub Desktop 3.4.19
GitButler 0.14.19, 0.14.18
Tower for Mac 13.0 (BETA) (Release blog post)

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Junio Hamano, Lucas Seiki Oshiro, Luca Milanesio, Thalia Rose, Elijah Newren, Toon Claes, Lee Reilly, Bruno Brito and Štěpán Němec.

Git Rev News Edition 121 (March 31st, 2025)

chriscool — Mon, 31 Mar 2025 11:06:51 +0000

Git Rev News: Edition 121 (March 31st, 2025)

Welcome to the 121st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of February and March 2025.

Discussions

General

10 years of Git Rev News

Git Rev News started 10 years ago with edition 1 published on March 25, 2015, and then one edition per month.

To celebrate, let’s look at some stats that we have gathered about these first 120 editions.
- First we would like to thank all those who helped us so far.
  
  This includes those who helped with ideas, links, PRs, small corrections, letting us know about a Git related software release, and even sometimes full articles without being part of our editor team. Here is the top 12 along with the number of editions they helped us with, according to our “Credits” section, and the number of commits they contributed:
  - Johannes Schindelin: 29 editions and 71 commits
  - Bruno Brito: 25 editions and 36 commits
  - Luca Milanesio: 19 editions and 23 commits
  - Štěpán Němec: 18 editions and 22 commits
  - Junio Hamano: 13 editions and 22 commits
  - Philip Oakley: 10 editions and 10 commits
  - Elijah Newren: 10 editions and 9 commits
  - Andrew Ardill: 8 editions and 15 commits
  - David Pursehouse: 8 editions and 12 commits
  - Jeff King: 8 editions and 5 commits
  - Matthieu Moy: 6 editions and 14 commits
  - Lars Schneider: 6 editions and 14 commits
  In total, more than 125 people helped this way.
  
  Former members of the editor team helped a lot, too:
  - Thomas Ferris Nicolaisen: 33 editions and 135 commits
  - Gabriel Alcaras: 22 editions and 7 commits
  - Nicola Paolucci: 16 editions and 5 commits
  A small number of people have also helped us by contributing to our scripts to automate parts of the edition and publication process:
  - Gabriel Alcaras: 9 commits
  - David Aguilar: 3 commits
  - Mirth Hickford: 2 commits
- A number of people helped by accepting to be interviewed in our “Developer Spotlight” or “Community Spotlight” sections. Thanks to them, too:
  - Total interviews: 72
  - Unique interviewees: 70
  - Repeat interviews: 2 (David Aguilar and Eric Sunshine have been interviewed twice)
  - Developer interviews: 70
  - Community interviews: 2
- Most of the long articles are in a “Discussions” section and in one of its subsections: “General”, “Reviews” or “Support”. Here are some related stats:
  
  Total over all the editions:
  - Discussions articles: 254
  - General articles: 106
  - Reviews articles: 79
  - Support articles: 69
  Average per edition:
  - Discussions: 2.12
  - General: 0.88
  - Reviews: 0.66
  - Support: 0.57
  Text Statistics:
  - Total words: 100,434
  - Total lines: 14,090
  - Total paragraphs: 3,097
  Average per article:
  - Words: 395.4
  - Lines: 55.5
  - Paragraphs: 12.2
  Total words per section:
  - General: 29,220 words
  - Reviews: 35,912 words
  - Support: 35,302 words
- Among those long articles, 16 articles were written by people outside the editor team. Big thanks to them! The top 3 is:
  - Junio Hamano: 4
  - Matthieu Moy: 3
  - Jacob Keller: 2
  The following people wrote one article each:
  
  Andrew Ardill, Elijah Newren, Eric S. Raymond, Eric Sunshine, Jiang Xin, Lars Schneider.
  
  One article was also written collaboratively by the following students:
  
  François Beutin, Jordan De Gea, William Duclot, Samuel Groot, Erwan Mathonière, Antoine Queru, Simon Rabourg and Tom Russello.
  
  These articles were mostly written towards the first years of Git Rev News:
  - 2015: 8 articles
  - 2016: 2 articles
  - 2018: 2 articles
  - 2019: 1 article
  - 2020: 3 articles
- There were 2298 entries in the “Other News” section, which gathers links to various news, articles, sites, tools, and sometimes media about Git (or related to Git).
  
  Those entries include:
  - 1090 entries in “Light reading” over 114 editions with 1777 links; around 13.76% of entries mention previous editions.
  - 691 entries in “Git tools and sites” over 118 editions with 1270 links; around 11.72% of entries mention previous editions.
  - 411 entries in “Various” over 110 editions with 635 links; around 7.06% of entries mention previous editions.
  - 20 entries in “Events” over 12 editions with 39 links
  - 15 entries in “Easy watching” over 12 editions with 31 links; of those, 3 entries mention previous editions.
  There were quite a few one-off names of sub-lists, like “Slightly heavier reading”, “April Fool’s”, “Listening and watching”. The template with standardized names was not present in the 1st edition, but was created later.
Git participated in the December 2024 Outreachy round

All the Outreachy interns have successfully completed their internship:
- Seyi Kuforiji worked on the “Convert unit tests to use the clar testing framework” project, mentored by Patrick Steinhardt and Phillip Wood. See his completion email and his retrospect blog post.
- Usman Akinyemi worked on the “Finish adding a ‘os-version’ capability to Git protocol v2” project, mentored by Christian Couder. See his completion blog post.

Developer Spotlight: Peter Krefting

Who are you and what do you do?

My name is Peter Krefting and I am a software engineer. Hailing from Sweden, I moved to Norway for my first job, at Opera Software, mostly working on internals such as Unicode support and internal libraries. I ended up staying in Norway and am currently working for a small company providing monitoring equipment for digital TV.
What are you doing on the Git project these days, and why?

My answers to these two are the same, I am the maintainer of the Swedish translation of Git. I like having software running in my own language, and sometimes you have to take matters in your own hands.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I think git gui and gitk could need some extra love, these are my daily drivers, in addition to the command line.
Is there something that developers could do to ease the life of translators?

My main gripe is using library function names as verbs, like cannot fsync. That’s hard to read even in the original language, even for a C developer like myself.
What is your favorite Git-related tool/library, outside of Git itself?

I like simple and clean interfaces, so using cgit to visualize history on a web server is very nice.
What is your toolbox for interacting with the mailing list and for development of Git?

I mostly just read the mailing list, and only a small percentage of the posts to it; the localization is handled through GitHub pull requests, so that’s where that work happens. The few patches I have sent to the mailing list have been very manual, using git format-patch and the Alpine mail client.
What is your advice for people who want to start Git development? Where and how should they start?

Find some small part you want to improve, and work on that. Git is a fairly complex piece of software, implemented in several different languages, making it hard to get an overview. I most definitely do not have that, even after having read (and translated) most of the user-visible strings.

Other News

Various

What’s new in Git 2.49.0? by Toon Claes on GitLab Blog. This blog post mentions, among other things, improved performance thanks to zlib-ng, a new name-hashing algorithm, and git-backfill.
Highlights from Git 2.49 by Taylor Blau on GitHub Blog. Mentioned items include faster packing with name-hash v2, backfilling historical blobs in partial clones, building Git with zlib-ng, and the libgit-sys and libgit Rust crates.

Light reading

Going down the rabbit hole of Git’s new bundle-uri by Scott Chacon on GitButler blog.
The bundle-uri was mentioned in passing in Git Rev News Edition #95 (in “Developer Spotlight”) and in Edition #104 (in “Git tools and sites”, when mentioning git-bundle-server).
No Longer My Favorite Git Commit by Michael Lynch on his blog, talks about how one could improve the commit message described in David Thompson’s “My favourite Git commit” - which was mentioned in Git Rev News Edition #57 and #108.
- The article mentions the How to Write Useful Commit Messages guide by Michael Lynch, one of the sample chapters for his prospective book, “Refactoring English: Effective writing for software developers”.
- Another post by Michael Lynch, How to Make Your Code Reviewer Fall in Love with You, was mentioned in Git Rev News Edition #70.
19000 curl commits by Daniel Stenberg on his blog, presenting some statistics about those commits.
Why fastDOOM is fast by Fabien Sanglard, examines FastDOOM performance evolution over time, doing some nice Git archeology.
Personal Agency With Git Time Logging by Doug Bridgens on doocot blog. The commit-msg and pre-push hooks from git-time-hooks are used to measure time spans from creating a new branch to merging that branch.
git bisect … by Mohammad Sajid Anwar (MANWAR) on The Weekly Challenge blog. The blog post shows how to use git bisect on a detailed example (in Perl).
Python monorepo with uv and pex by Christoph Pröschel on his blog. The article discusses the benefits of a lightweight solution built with regular Python tooling over, for example, the Pants build tool, because it was easier to justify its adoption for the rest of the team.
- You can find a definition of “monorepo” and a list of various tools on the Monorepo.tools site, which was first mentioned in Git Rev News Edition #84.
Gerrit Code Review: A How-To Guide for new users! by Daniele Sassoli on GerritForge Blog. See also:
- How GitHub taught the world code review the wrong way by Daniele Sassoli (2024) on his Medium-based blog.
- Pull requests / Collaborate with pull requests / Getting started / Helping others review your changes on GitHub Docs.
TIL: Hugo’s GitInfo by Dionysis Grigoropoulos, about the GitInfo method of Hugo, the static site generator in Go. The method returns Git information related to the last commit of the given page.
GitHub meets GitLab by Mohammad Sajid Anwar (MANWAR) on The Weekly Challenge blog, about the terminology differences between GitHub and GitLab (part of the learning process to pick up GitLab).
Comparing Git Mirror Options: by Lloyd Atkinson on his blog. The tools considered include gitweb, cgit, and Forgejo; the last option (Forgejo) was ultimately selected.
Migrating git.adyxax.org from gitolite and cgit to Forgejo: How I am deploying Forgejo with Ansible. By Julien (Adyxax) Dessaux on his blog.
Learn Git through Gamification – A Visual Guide to Key Version Control Concepts by Jacob Stopak on freeCodeCamp.
4 reasons you need to run a Git server on your NAS (even if you’re not a developer) by Adam Conway on XDA Developers.
Manage DNS Records with GitHub Actions and DNSControl by John Wq on [runtimeerror] blog.
WSL SSH agent and Git by Patrik Trefil (2024) on his blog. This article describes how you can avoid the hassle of copying and pasting your SSH passphrase every time you want to connect to a machine via ssh.
Accessing git Servers Over Another Port When 22 is Blocked and Cloning Hangs Waiting for Connection by Jayson Salazar Rodriguez (2024) on his site.
Automatic Versioning with Xcode and Git by Rat Troupe on Reiterations blog (2024).
Version controlling Jenkins config by Kaushal Modi (2022) on A Scripter’s Notes; mentions jenkins-plugin-cli from Plugin Installation Manager Tool for Jenkins.
- Compare How to use the Jenkins Git Plugin: Tips and tricks by Cameron McKenzie from Git Rev News Edition #44, about Git | Jenkins Plugin.
Using Git Delta with Magit by Kaushal Modi (2022) on A Scripter’s Notes.
- Delta is a highly configurable command line utility that makes the Git diffs look better, while also syntax-highlighting the code in the diffs. First mentioned in Git Rev News Edition #86.
- Magit is a popular Emacs interface to Git, first mentioned (in passing) in Git Rev News Edition #6.
How to Proxy Git Connections: using socat to …Git… through a corporate firewall by Bryan Brattlof (2022) on his blog.
Git aliases supporting main and master: How to make your aliases agnostic to the default branch by Philipe Fatio (2022) on his blog.
Keeping ‘live‘ dotfiles in a Git repo by creating a repository directory named .dotfiles/ rather than .git/ via the --git-dir Git wrapper option. From https://probablerobot.net/ (2021).
On mainline merges and fast forwards by aoeuo (2008) on the Blogger-based DVCS Comparison blog. Compares Bazaar with Git and Mercurial.
GPLv2 is not impressed by git by Thomas Huehn on his Bear-powered blog, a short musing about the following phrase from the license:

You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change.
I found commit 0 (or rather a commit whose SHA-1 identifier begins with 0000000), by Kissaki on the programming.dev Lemmy instance.
Lemmy is a self-hosted, federated social link aggregation and discussion forum, somewhat similar to Reddit.
- Note that there are tools like git-vain and git-vanity-sha, most recently listed in Git Rev News Edition #103, which can be used to make the SHA-1 hash of a commit start with a specific pattern, like 000000, by manipulating the commit date or message.

Easy watching

What Git Clone REALLY Does (and why it matters) on The Modern Coder YouTube channel, 3:16 minutes long. It’s made by @JackLot who created the LearnGit.io resource, which site was mentioned in Git Rev News Edition #108.
Git Interview Part 1: Easy | Ep. 8 Bits and Booze [29:09] and
Git Interview Part 2: Hard | Ep. 9 Bits and Booze [17:45]
on the GitButler YouTube channel. Join Nico as he (mock) interviews Scott [Chacon] about Git.

Git tools and sites

git-who is a command-line tool for finding the people responsible for entire components or subsystems in a codebase. You can think of git-who as a sort of git blame but for file trees rather than individual files. Written in Go under MIT license.
chrondb (repo) is a chronological key/value database, where storing data is based on database-shaped git (core) architecture and Lucene for indexing. Written in Clojure, uses MIT license.
Calendar.txt is a solution to keep your calendar in a plain text file. One of its advantages is that it is versionable: because it’s plain text, you can keep it in Git. You can also easily take diffs of calendar files, as it’s one day one line.
- See also Todo.txt to keep your TODO list in a plain text file, and tools like Taskwarrior and Plain Text Accounting (PTA).
YSK there are open-source (gamified) tutorials to learn git provides a list of some tutorials and interactive learning tools, including:
- Oh My Git!, an open source game about learning Git, first mentioned in Git Rev News Edition #72.
- Learn Git Branching, visual and interactive way to learn Git on the web, first mentioned in Git Rev News Edition #30.
- Git Gud: Master Git Through Play, a modern website to learn Git commands and concepts through an interactive game.
- Git+ Coach, a free education app designed to help users learn Git and its commands. Written in Kotlin, for Android.
- Git-it is a desktop (Mac, Windows and Linux) Electron app that teaches you how to use Git and GitHub on the command line. First mentioned in Git Rev News Edition #7.
BeanHub is a modern accounting book app based on the most popular open source version control system Git and the text-based double entry accounting book software Beancount. Mostly open-sourced. See also the following posts by Fang-Pen Lin:

Releases

Git 2.49.0, 2.49.0-rc2, 2.49.0-rc1
Git for Windows 2.49.0(1), 2.49.0-rc2(1), 2.49.0-rc1(1)
Gerrit Code Review 3.10.5, 3.11.2, 3.9.10
GitLab 17.10.1, 17.9.3, 17.8.6, 17.10, 17.9.2, 17.8.5, 17.7.7
GitHub Enterprise 3.16.1, 3.15.5, 3.14.10, 3.13.13, 3.12.17, 3.16.0, 3.15.4, 3.14.9, 3.13.12, 3.12.16
GitKraken 11.0.0, 10.8.0
GitHub Desktop 3.4.18
GitButler 0.14.14, 0.14.13
git-credential-azure 0.3.1
git-credential-oauth 0.15.0
Tower for Mac 12.6
Tower for Windows 9.0 (Release blog post)

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Peter Krefting, Bruno Brito, Daniele Sassoli, Toon Claes and Štěpán Němec.

Git Rev News Edition 120 (February 28th, 2025)

chriscool — Fri, 28 Feb 2025 11:06:51 +0000

Git Rev News: Edition 120 (February 28th, 2025)

Welcome to the 120th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of January and February 2025.

Discussions

Reviews

[PATCH] worktree: detect from secondary worktree if main worktree is bare

Last November, Olga Pilipenco sent a patch to the mailing list addressing an issue she had encountered while working with multiple worktrees.

Git worktrees allow developers to check out multiple branches from the same repository simultaneously, each in its own working directory. Unlike creating separate clones, worktrees share the same object database and references, saving disk space and avoiding the need to push and fetch between copies of the repository. They can be very useful when working on multiple features in parallel or when needing to make a quick fix while in the middle of other development work.

The issue happened when a repository had a main worktree that was bare with core.bare = true in config.worktree. After creation of a new secondary worktree, from that secondary worktree’s point-of-view the main worktree appeared as non-bare. This prevented users from checking out or working with the default branch of the main worktree (typically “main” or “master”) in the secondary worktree.

When extensions.worktreeConfig is enabled, each worktree has its own configuration settings in a config.worktree file that can override repository-wide settings in the common config file. This allows different worktrees to have different configurations, but it also means that settings from one worktree aren’t automatically visible to commands running in another worktree.

Olga found that when inside the secondary worktree, the main worktree’s configuration wasn’t initialized, and her patch fixed that by loading the main worktree’s config.worktree file only when required.

Unfortunately Olga’s email fell through the cracks, receiving no response. But last January she sent a version 2 of her patch. There was no code change compared to the first version, but she added people in “Cc:”, and she had rebased the patch on top of the “maint” branch.

This time Eric Sunshine replied. He acknowledged that this was a real problem and noted that it had been documented in a “NEEDSWORK” comment added in 2019 to the code which now got patched. He then attempted to rewrite the commit message of the patch in a way that was “more idiomatic” to the project and that added more details to help understand the problem.

The suggested commit message especially mentioned that when extensions.worktreeConfig is true, commands run in a secondary worktree only consulted $commondir/config and $commondir/worktrees/<id>/config.worktree. Thus they never saw that the main worktree’s core.bare setting was true in $commondir/config.worktree.

Eric also suggested removing some parts of Olga’s commit message that talked about other solutions she had considered, or repeated in which circumstances the problem appeared. Finally, there were a number of small comments on the code part of the patch.

Olga replied to Eric saying that the commit message he proposed was “so much better” than the original one. She agreed with most of Eric’s suggestions and answered the few questions he asked.

Eric replied explaining some technical details and making a few more suggestions.

Junio Hamano, the Git maintainer, then replied to Eric thanking him “for an easy-to-read review” and thanking Olga for working on this issue.

Eric and Olga further discussed technical improvements to the patch. In the course of that discussion, Eric explained the historical context related to using the “bare main worktree” expression:

It’s a historic “accident” that when worktree support was designed, the idea of linking worktrees to a bare repository was not considered. Support for using worktrees with a bare repository was added later. However, by that time, the term “main worktree” was already well established, with the very unfortunate result that even when there is no actual “main worktree” but only a bare repository with “linked worktrees” hanging off it, the repository itself is usually referred to as the “bare main worktree”, which is an obvious misnomer; the repository is just a repository (i.e. the object database and other meta-information) and there is no actual main worktree.

Olga then sent a version 3 of her patch. It used the commit message suggested by Eric, and implemented his suggestions.

Junio reviewed this new version of the patch and had a single question about the code that decided when it was necessary to read the main worktree’s config.worktree file. Olga and Junio further discussed how to make it clearer what that code was doing, and eventually agreed on adding a four line long comment on top of it.

Olga then sent a version 4 of her patch which only added that four line long comment.

The patch was later merged into the ‘master’ branch, so version 2.49 of Git, which should be released in a few weeks, will finally resolve a long-standing issue and significantly enhance the usability of Git worktrees for developers working with bare repositories.

Community Spotlight: Chris Torek

Chris Torek has been a prolific contributor to the Git topic on Stack Overflow. This edition features an interview with him. This is a continuation of our initiative to interview community contributors outside of our mailing list. Our first interview was with VonC in edition 106.

Who are you and what do you do?

“Who am I” is way too complicated! 🙂 What I do … well, I’m now retired, and you’d think that would give me more time to answer things like this.

I used to do a lot of embedded systems programming, and a lot of internal company education at times (about programming languages, various hardware functions and limitations, software tools, and such). That’s what led me to answering Stack Overflow questions.
What would you name your most important contribution to Git?

I haven’t put much into Git itself. I fixed a minor issue with case-insensitive rename once, and something that was annoying me about git diff applied to merge commits [ref].
What was your motivation behind answering questions about Git on Stack Overflow?

Here, well, I got roped into explaining Git to a group that was moving from Mercurial. I found existing descriptions to be lacking. Eventually that particular job went away but the question-answering persisted, until I got sufficiently annoyed at Stack Overflow itself (for various reasons) to take a break that continues to this day.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’m not entirely sure. There are a few big issues today, such as dealing with OS irregularities (the fact that Windows can’t name a file aux.h for instance is a trivial example of the overall problem; very long file names, case and UTF-8 encoding sensitivities are another example of the same underlying issue); the ongoing transition from SHA-1 to SHA-256 (which works now but there’s no cross-compatibility); a number of minor but sometimes important niggles with merging; support for extremely large code bases, including submodules and other ideas (Microsoft’s Git VFS). I have no ideas for how to achieve this but a better way to “see” history would, I think, be a huge improvement.

One other thing that might be particularly good is an equivalent of Mercurial’s evolve extension. But even Mercurial’s was never mainstreamed; this is very hard to get right (whatever “right” means).
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I’m not convinced anything needs to be removed, but it would simplify things a lot if we didn’t need SHA-1 compatibility, if SHA-256 magically just worked and everything were converted over. (And looking at VonC’s reply I agree that switch+restore is a much better split than the old checkout.) And, although people like it for convenience, it might be OK if we all had to use separate fetch-then-(whatever is needed) steps: see below.
What is your favorite Git-related tool/library, outside of Git itself?

I don’t think I have one. I’ve used gitk for history browsing, and if it were somehow improved (see the list of items above) it might be particularly useful.
What is one of your most favourite features of Git?

Speed. Having used the previous generations of version control (and waited, and waited…), there’s nothing quite like doing an update and having it take only seconds. The distributed nature is also pretty crucial, though it has its pluses and minuses.
Could you brief a bit about one of your most memorable experiences with Git?

Hah, the most memorable one was probably one of the worst, back in the days of Git 1.5 or so. Back then, an initial git pull wasn’t always careful about a pre-populated working tree. I had it destroy a week’s worth of code once. Ever since then I’ve separated pull into fetch followed by merge-or-rebase. This is long since fixed, but it’s instructive to new users to know that pull is really two separate steps. When I started, I didn’t know that: the tutorial I read just said to run git pull.
What is your advice for people who want to start using Git? Where and how should they start?

I’m not entirely fond of any of the introductions I’ve seen. I started on a book once (between jobs) but stalled out when I went to work for another startup. One of these days I plan to get back to it.
There’s a common conception that “Git is confusing”. What are your thoughts about the same?

There are confusing parts, but they are inherent to the issues that occur with distributed repositories and independent development. The only way to really understand this is to get a good grounding—hence the idea of writing a book.
If there’s one tip you would like to share with other Git developers, what would it be?

For developers in particular, they should probably have a look at what surprises Git users. If something didn’t work the way someone expected it to, why? Was it an incorrect expectation (it probably was) and if so, why did the user have that expectation in the first place?

Other News

Various

The Git project has been accepted as a Mentor Organization for Google Summer of Code (GSoC) 2025. We can still add project ideas to our idea page, and volunteers to (co-)mentor are still welcome. Feel free to join the discussion in the corresponding thread. Also, feel free to spread the word about Git’s participation.
GitHub - Repositories – Updated insight views (General Availability) in GitHub Changelog.

Light reading

Why was Git Autocorrect too fast for Formula One drivers? Why did Git’s autocorrect wait 0.1s before executing a mistyped command? Post by Scott Chacon on GitButler Blog.
How Core Git Developers Configure Git by Scott Chacon on GitButler Blog.
- See also Popular git config options by Julia Evans on her blog, which was mentioned in Git Rev News Edition #108.
How to do patch-based review with git range-diff by Scott Chacon on GitButler Blog.
Markdown’s Big Brother: Say Hello to AsciiDoc by Marvin Blome on Git-Tower Blog.
- Another similar file format for textual data and technical documentation is reStructuredText (RST, ReST, or reST). It is used, among others, by the Python programming language community, and is part of the Docutils project of the Python Doc-SIG.
Understanding the Trunk-Based Development Workflow by Bruno Brito on Git-Tower Blog (2024).
- See also the https://trunkbaseddevelopment.com site, first mentioned in Git Rev News Edition #24.
One PC, Multiple Git Configs (This Will Save You Time!) with includeIf, a short post by Matteo Pampana on Medium.com.
Why Some Source Code Files Shouldn’t Be Managed via Git-Based Version Control on IT Security Guru.
Git Stash Without the Branch Name post by Brandon Pugh.
Microsoft Engineers Highlight Git Repository Bloat Flaw by Adrian Bridgwater on DevOps.com blog (2024).

Git tools and sites

JJ (Jujutsu) Cheat Sheet by Justin Pombrio.
- Jujutsu (jj), a Git-compatible version control system, written in Rust, was first mentioned in Git Rev News Edition #85.
Beej’s Guide to Git.
Gookme is a simple and easy-to-use, yet powerful and language agnostic Git hook manager for monorepos. Successor of Mookme. Written in Go, under MIT license.

Releases

Git 2.49.0-rc0
Git for Windows 2.49.0-rc0(1), 2.48.1(1)
GitHub Enterprise 3.16.0, 3.15.3, 3.14.8, 3.13.11, 3.12.15
GitLab 17.9.1, 17.8.4, 17.7.6, 17.9, 17.8.2, 17.7.4, 17.6.5
GitKraken 10.7.0, 10.6.3
GitHub Desktop 3.4.17, 3.4.16
Sourcetree 4.2.11
tig 2.5.12, 2.5.11
Garden 2.1.0
Git Cola 4.12.0
GitButler 0.14.8, 0.14.7
Tower for Mac 12.5, 12.5.1, 12.5.2 — Release blog post

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Chris Torek, Štěpán Němec, Bruno Brito and Brandon Pugh.

Git Rev News Edition 119 (January 31st, 2025)

chriscool — Fri, 31 Jan 2025 11:06:51 +0000

Git Rev News: Edition 119 (January 31st, 2025)

Welcome to the 119th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of December 2024 and January 2025.

Discussions

Support

git support for “xattrs” (extended filesystem attributes)?

Peter B. asked on the Git mailing list if there was a way to store extended attributes (xattrs) in Git. His use case was professional archival collection and he needed bit-proof preservation of all xattrs, even larger ones.

Junio Hamano, the Git maintainer, replied that Git only tracks “contents, pathnames where these contents are stored, and the executable bit”.

Jeff King, alias Peff, also replied to Peter confirming that Git, like most other version control systems, doesn’t store most metadata, but pointing to other tools, etckeeper and metastore, that can help with storing them in a separate file and restoring them on checkout.

Junio agreed with Peff that Git is extensible that way.

brian m. carlson replied to Peter mentioning other possibilities. One is to use the .gitattributes files to store a few xattrs with values that are “well stored as text”, and then git ls-attr and a post-checkout hook to restore them.

Another possibility is to use mtree utilities to store or restore metadata from or into mtree files. brian especially pointed to go-mtree which supports xattrs. As mtree is an extensible key-value format, brian uses it to store the install location of his dotfiles.

Peter replied to brian thanking everyone for the suggestions and saying he would especially take a look at mtree and metastore. He thanked brian again in the following message, saying that go-mtree looked very promising and that he was going to look at post-checkout hooks.

Developer Spotlight: Justin Tobler

Who are you and what do you do?

My name is Justin Tobler and I am a relatively new contributor to the Git project with my first contributions being made this last year. I work at GitLab and these days spend my time integrating Git into GitLab’s data access layer as well as upstreaming Git fixes/features.
What would you name your most important contribution to Git?

Most of my contributions thus far have been relatively minor bug fixes, but one bug I found particularly interesting was with the table compaction algorithm in the new reftable reference backend. There was a theoretical scenario where certain Git operations could be performed and new tables written, but table compaction would never occur. This was found when tests on certain platforms started failing because of file descriptor limits being exceeded.
What are you doing on the Git project these days, and why?

One topic I’m currently working on is introducing a way to generate batches of specific blob diffs. This is not particularly useful for users, but for Git servers it’s a nice feature.

I still have much to learn about the project so I also enjoy looking into the inflight topics that pop on the mailing list.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I don’t have anything specific in mind, but it would probably be along the lines of changes to make the Git CLI more consistent across its various commands.
What is your favorite Git-related tool/library, outside of Git itself?

For my Git-related workflow, outside of GitLab, I primarily use the Git CLI for everything.
What is your toolbox for interacting with the mailing list and for development of Git?

For interacting with the mailing list my workflow primarily consists of using neomutt and git send-email, but I have also recently been exploring b4.

For development, I use neovim as my editor with an assortment of plugins.
What is your advice for people who want to start Git development? Where and how should they start?

If you are unfamiliar with the mailing workflow, GitGitGadget can help handle formatting patches and sending them off to the mailing list. My first couple of patch series used this tool and I found it useful to get started without having to be super familiar with git format-patch and git send-email. Other than that, I also find it very helpful to observe how other contributors submit patches and interact on the mailing list.
If there’s one tip you would like to share with other Git developers, what would it be?

I appreciate when the authors of a patch series provide as much background as possible to the change being made. Reading incoming patch series is a great way to learn about the project and it is very helpful when the required context overhead is minimized.

Other News

Various

Highlights from Git 2.48 by Taylor Blau on GitHub Blog, about faster SHA-1 computations for checksums, adding option --remerge-diff to the git range-diff command, memory-leak-free tests, introducing the Meson build system, and more.
What’s new in Git 2.48.0? by Christian Couder on GitLab Blog, about the Meson build system, Git becoming memory-leak-free, improved bundle URI checks, adding reference consistency checks, more performant ‘reftables’ implementation, support for reflogs in git-refs migrate (to migrate to ‘reftables’), the ‘ref-filter’ subsystem optimizations, and more.
Git security vulnerabilities announced by Taylor Blau on GitHub Blog: CVE-2024-50349 (ANSI escape sequences in hostname and prompt for interactive credentials) and CVE-2024-52006 (specially-crafted repository URL and credential helpers).
- See also Clone2Leak: Your Git Credentials Belong To Us by RyotaK (@ryotkak), a security engineer at GMO Flatt Security Inc.
Adam Johnson’s book “Boost Your Git DX” has been updated with 28 new pages of content. This book was first mentioned in Git Rev News Edition #104.

Light reading

Off-the-shelf governance models for small FOSS projects? by Antonin Delpeuch, about an idea for GOVERNANCE.md file template or generator, as another recommended addition to README.md, LICENSE, and Code of Conduct. Mergiraf’s GOVERNANCE.md is his example - the goal here is to make it clear for project users what one can do if there is an issue/bug, or if one wants to add a new feature to a project.
Re: DCO by Bradley M. Kuhn of Software Freedom Conservancy on GDB Development mailing list (via GDB public-inbox instance), about the considerations when adopting the Developer Certificate of Origin for a project (similarly to the Linux kernel and Git).
The many names of commit 55039832f98c by Jonathan Corbet on LWN.net, about difficulties finding the commit in mainline kernel repository that corresponds to the specific commit/patch sent to the stable-update mailing list, in the presence of DRM community’s wide use of cherry-picking (without something like “change ID” that is used by Gerrit).
The slow death of TuxFamily, a French free-software-hosting service, by Joe Brockmeier on LWN.net.
A Retrospective on the Source Code Control System by Marc J. Rochkind (PDF).
Considerations for making a tree view component (in a web Git UI) accessible by Eric Bailey on GitHub Blog.
Commit subject case in Git history analysis by D. Ben Knoble, as a blog post on his Junk Drawer site.
Colliding with the SHA prefix of Linux’s initial Git commit Or, how to break all the tools that parse the “Fixes:” tag, by Kees Cook on people.kernel.org. Note that the 12-character prefix collision was generated with the help of the lucky-commit project; this tool was mentioned in Git Rev News Edition #109.
- See also Facing the Git commit-ID collision catastrophe by Jonathan Corbet on LWN.net, mentioned in the previous edition.
How to set up your ~~own Git server~~ Gitea instance at home for your personal projects by Ty Sherback on XDA Developers.
- Gitea, a Go-based software forge (fork of Gogs), was first mentioned in Git Rev News Edition #23. There is also Forgejo, a fork of Gitea, mentioned in Git Rev News Edition #114.
Is there a way to split the git history of a file or combine the histories of two files without a merge commit?, a short exploration by Raymond Chen on The Old New Thing, part of Microsoft Dev Blogs.
- Some of the other blog posts referenced in the above-mentioned exploration also made their appearance in Git Rev News: Mundane git tricks: Combining two files into one while preserving line history was mentioned in Edition #51. How do I split a file into two while preserving git line history? was not present, but the related How to split off an older copy of a file while preserving git line history appeared in Edition #104.
Edit commit message with git reword (git commit --fixup:reword=<commit>) in Brandon Pugh’s TILs: Today I learned… (2024).
How I use git worktrees (with the help of custom worktree script) by Bill Mill on their blog (2024).
- See also How I Use Git Worktrees by Alex Kladov (matklad) on his GitHub Pages-based blog, mentioned in Git Rev News Edition #113.
Git Trailers by Brooke Kuhlmann was mentioned in Git Rev News Edition #108, but was since then updated.

Git tools and sites

Project Harmony (Harmony Agreements) is a community-centered group focused on contributor agreements for free and open source software (FOSS).
todo-md is a pre-commit hook written in Bash that automatically maintains a TODO.md file in your repository. It collects TODO: comments from your code and organizes them into a Markdown file, making it easy to track tasks and improvements. Under MIT license.
Yek (يک) is a fast Rust based tool to serialize (selected) text-based files in a repository or directory into a single file meant for LLM consumption. Mentions similar projects. Under MIT license.

Releases

Git 2.48.1 and friends (security releases), 2.48.0, 2.48.0-rc2
Git for Windows 2.47.1(2) (security release), 2.48.0-rc2(1)
GitLab 17.8.1, 17.7.3, 17.6.4, 17.8, 17.7.2, 17.7.1, 17.6.3, 17.5.5
Gerrit Code Review 3.10.4, 3.11.1, 3.9.9
GitHub Enterprise 3.15.2, 3.14.7, 3.13.10, 3.12.14
GitKraken 10.6.3, 10.6.2, 10.6.1
GitHub Desktop 3.4.15, 3.4.14, 3.4.13
Garden 2.0.0, 1.10.1
Git Cola 4.11.0
GitButler 0.14.6, 0.14.5

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Justin Tobler, D. Ben Knoble, Brandon Pugh, Štěpán Němec and Adam Johnson.

Git Rev News Edition 118 (December 31st, 2024)

chriscool — Tue, 31 Dec 2024 11:06:51 +0000

Git Rev News: Edition 118 (December 31st, 2024)

Welcome to the 118th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of November and December 2024.

Discussions

General

Git participates in Outreachy’s December 2024 to March 2025 round:
- Seyi Kuforiji is working on the “Convert unit tests to use the clar testing framework” project. He is mentored by Patrick Steinhardt and Phillip Wood and posting updates on his gitlab.io blog while his work is on his GitHub repository.
- Usman Akinyemi is working on the “Finish adding an ‘os-version’ capability to Git protocol v2” project. He is mentored by Christian Couder and posting updates on his hashnode.dev blog while his work is on his GitLab repository.
Congratulations to Usman and Seyi for being selected!

Thanks to GitHub for funding these two Outreachy internships!

Many thanks also to the other contributors who applied and worked on micro-projects, but couldn’t be selected! We hope to continue to see you in the community!

Support

./configure fails to link test program due to missing dependencies

Last September Henrik Holst reported an issue when trying to compile Git 2.44.0 with HTTPS/curl support on LFS 12.1. The configure script failed to detect libcurl’s dependencies properly when trying to link statically.

The issue occurred because the configure script only used the -lcurl build flag without running pkg-config --libs libcurl to add build flags for dependencies like zstd that libcurl needs. Henrik found that manually setting the LDFLAGS environment variable to include build flags for all dependencies (like -lcurl -lssl -lcrypto -lzstd -lbrotlidec -lz) allowed the build to succeed. This sparked a broader discussion about Git’s build system situation.

Looking at configure.ac, Junio Hamano, the Git maintainer, noted that pkg-config isn’t used at all, instead curl-config --libs is used to detect curl’s flags. Even though the configure script was added early in the history of the Git project, Junio said it was an afterthought and nobody has considered “upgrading” from curl-config to pkg-config for dependency detection.

In fact, our own Jakub Narębski initially added the configure script back in 2006 to make it much easier to create the RPM spec file for Git. Creating *.spec files is especially easy when the compilation follows traditional configure && make && make install steps.

brian m. carlson replied to Junio that users shouldn’t statically link libcurl or OpenSSL at all, as this creates security issues. With static linking, security updates to these libraries would require recompiling Git to take effect. In contrast, dynamic linking allows security updates to be applied as soon as a new Git process is spawned.

Patrick Steinhardt replied to Junio suggesting it might be time to reconsider Git’s three build systems (GNU Make, Autoconf, and CMake). He proposed potentially dropping Autoconf and making CMake officially supported, or switching to Meson as an alternative.

CMake was added more recently in 2020 by Sibi Siddharthan as the third build system with the main goal of improving the build experience for developers on Windows.

Soon after Patrick’s reply, the Git Contributors’ Summit took place, and the “Modern Build System” topic was discussed there. Patrick Steinhardt raised concerns about maintaining three different build systems while others were concerned about having good platform support and good Windows developer experience. This led to an extensive discussion about the merits of different build systems in the thread started by Henrik.

Eli Schwartz, the Meson maintainer, made a detailed case for preferring Meson over CMake, citing various CMake pain points and limitations. Phillip Wood agreed with Patrick about getting rid of Autoconf, but raised the importance of Visual Studio integration, since CMake was originally added to improve the Windows developer experience. Johannes Schindelin, alias Dscho, emphasized that CMake’s deep Visual Studio integration was crucial for Windows developers and cautioned against switching to alternatives that would make the Windows experience worse. It appeared that Visual Studio has Meson support via plugins though, which alleviated some concerns.

Paul Smith, the GNU Make maintainer, noted that requiring additional build tools like Meson, which are not yet often used and require some other dependencies, like Python3 for Meson, adds friction, though he acknowledged that for Git specifically this may be less of a concern given its existing dependencies.

Junio seemed to agree that adding support for a fourth build system would be worth it if it would allow the project to drop all other three build systems eventually. He said the new build system would have “to be something available widely and easy to learn”.

Patrick came up later in October with a 21 patch long RFC series to add support for the Meson build system with the goal of eventually replacing the current three build systems.

There were a number of iterations on that series. Among the many comments, Taylor Blau asked about the eventual goals of the series and plans for CMake support. He noted that CMake support in contrib/ was in an awkward position, neither fully supported nor properly maintained out-of-tree. He was concerned about having to maintain three build systems simultaneously during any transition period.

David Aguilar expressed concerns about Python being a dependency through Meson. Eli replied that muon, a C99 implementation of Meson, could be used instead and demonstrated it working with Git’s build.

Jeff King, alias Peff, asked about reliability for bisecting and whether out-of-source builds would work correctly when moving between commits. He also requested better documentation of common developer workflows with Meson compared to Make.

Junio discussed the need to maintain build system compatibility during any transition period. He noted that many of the Makefile options were added over time for good reasons and dropping support for them would need careful consideration.

A number of other developers participated in the reviews. Ramsay Jones tested the patches on various platforms including Cygwin. Phillip Wood reviewed CMake-related changes and provided technical feedback. Johannes Sixt commented on changes to the gitk-git subtree. Eric Sunshine provided technical feedback. Your own Christian Couder provided feedback on the documentation.

Over the iterations, Patrick updated the series to improve documentation, fix conflicts with in-flight patches, and address the various technical concerns raised during review.

Eventually version 11 of the patch series was merged and will be part of Git v2.48.0 that should be released in the next few weeks. It should be a properly supported modern build system that can be faster and more easily configurable than the three existing ones, which will hopefully get deprecated over time.

The merged patch series especially adds some documentation (via comments in meson.build) to help build Git with Meson and a build system comparison (in Documentation/technical/build-systems.txt) that might be interesting to read.

Other News

Various

Git 2.48-rc0 Released With git-fsck Warning Over “Curiously Formatted” Ref Contents by Michael Larabel on Phoronix.
Git Merge 2024 Talks are Up (on YouTube) by Scott Chacon on GitButler Blog. The article includes a quick summary of each of the talks.
Forgejo makes a full break from Gitea by Joe Brockmeier on LWN.net (from February 23, 2024).
- Gitea, which is Go-based software forge, a fork of Gogs, was first mentioned in Git Rev News Edition #23;
  Forgejo, which started as a “soft” fork of Gitea, was first mentioned in passing in Git Rev News Edition #103, and again in Edition #114.
EMERALDWHALE exploits vulnerable Git configuration files by Ryan Daws on Developer Tech News, about a global operation known as EMERALDWHALE, which has stolen over 15000 cloud service credentials by exploiting exposed Git configuration files (via misconfigured web services, which were exposing the .git directories of private repositories).
Abusing Git branch names to compromise a PyPI package (caused by a project automatically processing pull requests with a flawed script), short post by daroc on LWN.net.

Light reading

NonStop discussion around adding Rust to Git by Daroc Alden on LWN.net. The Git project discussed the prospect in January 2024, and then again at the Git Contributors’ Summit in September 2024.
- The Git Contributors’ Summit 2024 was mentioned in Git Rev News Edition #115, with links to notes as posts to the Git mailing list (also available in read-only Google Docs) and a repo with notes from the breakout unconference sessions.
Vigilante Justice on GitHub: GitHub Graffiti by Dylan Ayrey on The Dig (Truffle Security Co. blog), about how you can paint funny pixel art (graffiti) with fake commit Git histories on spammer/phisher’s GitHub profiles (on their activity heatmap plot) - which is [only] possible because of spammer attempts to leverage GitHub issues for phishing, on a repo one has push access to.
Facing the Git commit-ID collision catastrophe (in Linux kernel repository) by Jonathan Corbet on LWN.net, about the concern that, given the growth of the kernel repository, soon 12 digits will not be enough; on the other hand, commits only make up about 1/8 of the total objects in the repository, and abbreviated hashes should be accompanied by the short-form version of the changelog (--format=reference).
Optimizing Your Repository for Speed and Efficiency and Using Git Maintenance in GitHub Actions: Optimize Your Repositories Automatically posts by Emanuele Bartolesi for This is Learning on DEV.to constitute the 2 part series Streamline Your Workflow with the Git Maintenance Command.
- The git maintenance command was mentioned in Git Tips 2: Some Subtle New Things article on GitButler Blog by Scott Chacon, which in turn was mentioned in Git Rev News Edition #108.
Demystifying git submodules by Dmitry Mazin on his blog.
Fearless Rebasing by Scott Chacon on GitButler Blog is about “first class” conflict support in GitButler, based on the Jujutsu concept of “first class conflicts”.
- The article does not mention the built-in (but optional) git rerere mechanism of reusing recorded resolutions of conflicting merges (described for example in Git Tools - Rerere section in “Pro Git” 2nd Edition), that can help when rebasing repeatedly.
- In order to reduce the pain of resolving merge conflicts, and allow a merge or a rebase to be saved, tested, interrupted, published, and collaborated on while it is in progress, one can also use git-imerge tool (see also git-imerge: A Practical Introduction article).
  git-imerge was first mentioned in passing in Git Rev News Edition #17, while Edition #34 includes Developer Spotlight: Michael Haggerty, an interview with the author of this tool.
- Jujutsu (jj), a Git-compatible version control system, written in Rust, was first mentioned in Git Rev News Edition #85.
Stacked Branches with GitButler by Scott Chacon on the GitButler Blog. With the 0.14 release, GitButler can now manage dependent branches that are stacked, including managing stacked GitHub PRs (Pull Requests).
- See also Understanding the Stacked Pull Requests Workflow by Bruno Brito on Tower’s blog, mentioned in Git Rev News Edition #111 together with various other articles and tools about stacked diffs, stacked PRs, and stacked branches.
- See also Rethinking code reviews with stacked PRs by Ankit Jain on the Aviator blog, mentioned in Git Rev News Edition #115 with links to more sites and tools related to stacked PRs, etc.
~~Enforcing~~ Git Branch Naming Standards: ~~Tools and~~ Tips for Developers by Ojay on DEV.to (despite the title, the article does not include any technical way of helping to enforce or even remind of branch naming conventions).
9 ways to manage large creative projects with version control tools by Ruby Helyer on XDA Developers. Mentions CI/CD, Git LFS, commit message and file naming conventions.
Adam Ruka posted a series of articles on working with the Git source control system:
1. GitFlow considered harmful (2015)
2. Follow-up to ‘GitFlow considered harmful’ (2015)
3. OneFlow – a Git branching model and workflow (2017)
4. Implementing OneFlow on GitHub, BitBucket and GitLab (2021)
GitFlow: A successful Git branching model was a blog post by Vincent Driessen from 2010, with a note of reflection from 2020; the original author now suggests adopting a much simpler workflow (like GitHub flow) if the team is doing continuous delivery of software, and using GitFlow only when necessary, for explicitly versioned software - with multiple versions of it in the wild to be supported.
See also Patterns for Managing Source Code Branches by Martin Fowler, mentioned in Git Rev News Edition #63.

Git tools and sites

bus-factor-explorer by JetBrains Research is a web app for exploring the Bus Factor of GitHub projects by analyzing the commit history. Preferably run as a Docker image. The repository includes evaluation results for 935 popular repositories on GitHub. There is also a short video about the tool on YouTube: https://youtu.be/uIoV79N14z8. Written in Kotlin (with evaluation done with Jupyter notebooks), under MIT license.
- See The Bus Factor and The github plugin my coworkers asked me not to write articles mentioned in Git Rev News Edition #117 (the previous edition), together with accompanying links.
Anonymous GitHub is a service that allows you to anonymize your GitHub repository for double-blind scientific reviews (of scientific articles where source code is to be made available for open science reasons). Several anonymization options are available to ensure that you do not break the double anonymization, such as removing links, images or specific terms. The goal is to make is as easy as possible for the reviewer to explore and review the repository.
Git.News is a website which provides an infinite newsfeed of trending repositories from GitHub, HackerNews & Reddit (which you can then filter by programming language).
Octobox is a service to help manage GitHub notifications. Includes an optional GitHub app to add live information on issue, PR, CI status, labels, authors, etc. Octobox is free for open source projects and the use of basic notifications is free for private projects.
Filestash is a Dropbox-like enterprise-grade file manager, connecting your storage with your identity provider and authorisations. It adds a web interface to storage solutions like S3 buckets, SFTP/FTPS servers, Git repositories, etc. Self-hosted deployment is free; it can be done using a Docker image. Written in Go and JavaScript, under AGPLv3 license. Demo available at https://demo.filestash.app/, source code at https://github.com/mickael-kerjean/filestash.
DistGit (Distribution Git) is Git with additional data storage, designed to hold content of source RPMs (Linux distribution packages). Written in Python, under MIT license, but with scripts/httpd/upload.cgi under GPLv1, and the dist-git-client subdirectory under GPLv2+.
wikmd is a file-based wiki, with documents written in Markdown, which uses Git for version control. It is possible to connect Wikmd with an online repo. Written in Python, under MIT license.
Mycorrhiza Wiki is a free and open-source wiki engine, with data stored as simple files, and changes stored in Git. It uses Mycomarkup, a custom-made markup language, with support for transcluding units of contents. Written in Go, under AGPLv3 license.
Gitit is a wiki engine written in Haskell, that uses Happstack (HAppS) for the web server and pandoc for markup processing (with extended Markdown format as default). Pages and uploaded files are stored in a Git, darcs, or Mercurial repository and may be modified through the wiki’s web interface. Under GPLv2 license.
Xandikos is a lightweight CardDAV/CalDAV server that keeps history and backups in a Git repository. It allows to share calendars (events, todo items, journal entries) via CalDAV and contacts (vCard) via CardDAV. Written in Python using Dulwich, Jinja2, icalendar, and defusedxml, licensed under GPLv3+.
Opengist is a self-hosted pastebin powered by Git, similar to GitHub Gist. Demo available at https://demo.opengist.io/. Written in Go, under AGPLv3 license.
rgit is a gitweb/cgit-like fast web frontend for Git repositories. You can see it in action at https://git.inept.dev/. Written in Rust using Axum, gitoxide, Askama and RocksDB. Under WTFPL license (which is not on the list of OSI approved Licenses, but is on the list of licenses that meet Debian Free Software Guidelines).
klaus is a simple, easy-to-set-up Git web viewer. Supports syntax highlighting, Markdown + RestructuredText (reST) rendering support, and code navigation using Exuberant ctags. Can be installed as Docker image or via pip. You can see its demo at http://klausdemo.lophus.org/. Written in Python, under an unnamed custom permissive license.
git-activity is a tool to record your Git activity across multiple (or all) repos, and read it optionally filtered by date, activity type (e.g. commit, branch creation, etc.) regex pattern, repo name regex pattern, branch name regex pattern, commit message regex pattern, and/or commit SHA (first seven characters) regex pattern. Useful for retroactively filling out a time sheet (or correcting a time sheet), finding that time you solved a problem similar to the one you’re working on now, etc. The log is stored in a plain text file. Source code on GitHub. Written as Bash shell script using AWK, licensed under (custom) CC BY-NC-SA 4.0 with Hippocratic License v3 ethical requirements.
git-branches-script is a convenience script that prints a menu of recent Git branches and allows you to switch to a new branch by selecting its corresponding number. Written as Bash shell script, no license provided.

Releases

Git 2.48.0-rc1, 2.48.0-rc0
Git for Windows 2.48.0-rc1(1), 2.48.0-rc0(1)
libgit2 1.9.0
GitHub Enterprise 3.15.1, 3.14.6, 3.13.9, 3.12.13, 3.11.19, 3.15.0, 3.14.5, 3.13.8, 3.12.12, 3.11.18
GitLab 17.7, 17.6.2, 17.5.4, 17.4.6
Gerrit Code Review 3.11.0
GitKraken 10.6.0
GitHub Desktop 3.4.12, 3.4.11, 3.4.10
Garden 1.10.0
Git Cola 4.10.1, 4.10.0
GitButler 0.14.4, 0.14.3

Credits

Git Rev News Edition 117 (November 30th, 2024)

chriscool — Sat, 30 Nov 2024 11:06:51 +0000

Git Rev News: Edition 117 (November 30th, 2024)

Welcome to the 117th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of October and November 2024.

Discussions

Support

Bug report: v2.47.0 cannot fetch version 1 pack indexes

Someone called ‘fox’ reported that when upgrading Git to v2.47.0 from v2.46.2 or a previous version, cloning from their website, which uses the old “dumb HTTP” protocol, stopped working. With v2.47.0 there is an error message indicating that some index files “differ in contents”.

Using git bisect, fox found the commit that introduced the issue. That commit implemented a check that verified that the index file downloaded from the remote was byte-for-byte identical with the index file generated locally from the Git objects downloaded as part of the clone.

That check failed because the remote had an index in the version 1 format, while the locally generated index was in a more recent format. And fox wondered if this was intentional.

Eric Sunshine replied to fox that he could reproduce the problem.

Jeff King, alias Peff, also replied to fox saying that the breakage was not intended. He thought that it was better to rely on the locally generated index, but that there should be no guarantee for it to be identical to the downloaded one.

Peff proposed a draft patch that discarded the downloaded version before generating an index, but said it was hacky and didn’t check that the content was the same. So he suggested a better solution.

He then proposed an improved draft patch, which implemented the better solution he had suggested by marking the downloaded index as temporary and then discarding it after a new one is generated.

Taylor Blau, who was the temporary Git maintainer while Junio Hamano, the usual maintainer, had some time off, replied to Eric and fox in the meantime confirming it was an unintentional breakage, and saying he was going to look at Peff’s patches.

Taylor then discussed with Peff the first draft patch and agreed with Peff that the solution implemented in the improved draft patch was better.

So Taylor reviewed Peff’s improved draft patch. He made some comments but found it good, and asked Peff to add a test and to propose it as a regular patch.

Peff replied to Taylor’s comments, proposed a draft test, and said he was going to work on a proper patch as well as some cleanups and refactors in the dumb HTTP code.

Taylor found Peff’s draft test “beautifully written”.

Peff then sent a series made of 11 patches to fix the issue, clean up the dumb HTTP code and fix a couple of other bugs or potential bugs he found in the process.

Taylor reviewed the patch series and discussed a few technical details with Peff. Overall he found the series good to go and eventually merged it.

Developer Spotlight: Ghanshyam Thakkar

Who are you and what do you do?

I am Ghanshyam Thakkar. I was an undergrad student in Electronics when I started contributing to Git. I am now a Software Engineer at a startup. I sometimes contribute to open source projects in my free time, and explore/learn new technologies.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your GSoC project?

Before GSoC, I was quite familiar with the Linux ecosystem, and it had been my primary OS for the majority of my college years. And during those times I felt Git was the most impactful project enabling the vastly collaborative Linux Desktop Ecosystem. So, I felt like contributing to Git would be a great opportunity to learn and contribute to a project that had been so crucial to my everyday workflow.
How do you feel your contribution has impacted the Git community or the broader open source ecosystem?

Before my GSoC project, I had contributed some small patches, which could be considered as bug fix, general code cleanup, expanding test coverage, etc. Some of which can be observed in user-space. But my GSoC project was about migrating Git’s test suite to a purely C-based test framework, which was not user-facing, however, was a step in the right direction for the project as a whole.
Is there any aspect of Git that you now see differently after having contributed to it?

The mailing list workflow. Although, I was skeptical about it at first because I had never used mailing lists before, I now see it as a very effective way to communicate and collaborate on a project of such massive scale. Although, I still am not a big fan of the all or nothing nature of the mailing lists. Subscribing to mails of a specific area would have been great. Although, I do understand that it can probably be done with filtering using a script.
How do you balance your contributions with other responsibilities like work or school?

When I was contributing to Git as part of GSoC, I was a student and I also had summer vacation, so it was quite easy for me to balance my contributions with my personal life. However, now that I am quite busy with my $DAYJOB, I don’t have much bandwidth to contribute to open source in the short term. But I am planning to start contributing again after some time.
Can you share how GSoC helped enhance your technical and non-technical skills (like communication, project management, etc.)?

I would say it helped me improve my technical communication skills immensely. Going back and forth with the reviewers on the list, I learned quite a bit about how to communicate effectively. Also, this was my first time working in a C based project, so I learned some C hacks as well!
What was your biggest takeaway or learning from GSoC that you now apply regularly in your work?

Technical communication and effective code review. Also more effective Git usage.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

More than the technical challenges solving a problem, I would say it was more challenging finding the relevant work to do, as there is no official issue tracker. I would search for #leftoverbits on the mailing list and #TODOs in the codebase to find things to do. However, most of them seemed quite out of reach in terms of difficulty. However, I attempted them anyway and learned a lot in the process. The mailing list folks were quite helpful in guiding me in the right direction.
Have you thought about mentoring new GSoC students?

Yes, although I don’t have the bandwidth to become a primary mentor, I would love to be a co-mentor.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Honestly, I find Git to be quite mature and complete. I can’t think of anything, off the top of my head, that I would like people to work on for a full year.
What upcoming features or changes in Git are you particularly excited about?

Rust adoption.
What is your favorite Git-related tool/library, outside of Git itself?

I quite frequently find myself using lazygit on the command line for some quick and dirty Git operations.
What is your toolbox for interacting with the mailing list and for development of Git?

I use aerc and send-email/format-patch for email interactions. And for development, I use Neovim and clangd LSP with the GENERATE_COMPILATION_DATABASE build flag.
How do you envision your own involvement with Git or other open source projects in the future?

I think I will continue to be a part of the open source community in some way or the other. My perspective towards open source has always been very positive and I would like to continue contributing to it.
What is your advice for people who want to start Git development? Where and how should they start?

I would suggest to start from reading the docs, particularly MyFirstContribution and SubmittingPatches. And then start with some #leftoverbits or if you are particularly interested in a specific area, you can even reach out to people working on those areas to ask for guidance.
Would you recommend other students or contributors to participate in the GSoC, or other mentoring programs, working on Git? Why? Do you have advice for them?

Absolutely! GSoC is a great opportunity to learn and contribute to open source projects. It is a great way to learn how a project of such massive scale is managed and developed.

Other News

Light reading

The Bus Factor by Maryanne Wachter (also known as <mclare> or m-clare) on her blog (with visualizations built with Observable), and The github plugin my coworkers asked me not to write. by Shae Erisson on Shae Erisson’s Blog.
- The bus factor is a measurement of the risk resulting from information and capabilities not being shared among team members, derived from the phrase “in case they get hit by a bus”. It is also known as the bus problem, truck factor, bus/truck number or circus factor. The “bus factor” is the minimum number of team members that have to suddenly disappear from a project before the project stalls due to lack of knowledgeable or competent personnel. (From Wikipedia).
- Based on the “A Novel Approach for Estimating Truck Factors” paper from 2016 by Guilherme Avelino, Leonardo Passos, Andre Hora, and Marco Tulio Valente, with many citations since. Original implementation available at https://github.com/aserg-ufmg/Truck-Factor.
How we shrunk our Javascript monorepo git size by 94% Mentions using the git-sizer tool which was mentioned in passing in Git Rev News Edition #37. The work described in the article also led to adding the --path-walk option to git repack and the pack.usePathWalk config option to Git, and to the new experimental git survey command (that for now is present in Microsoft’s fork of Git),
Deleted your fork. Is it gone? Not really… by Marta Rybczynska on Ygreky Blog. Provides some recommendations for best practices when using public forges.
- References Anyone can Access Deleted and Private Repository Data on GitHub blog post by Truffle Security, mentioned in Git Rev News Edition #113.
- See also Demystifying GitHub Private Forks - The Hidden Danger of Cached View by Guillaume Valadon on GitGuardian Blog.
How I configure my Git identities with the help of git config features: includeIf with gitdir: and hasconfig:, complex ~/.ssh/config setups (and the use of insteadOf, where needed). Written by Benji Encalada Mora on their blog (with a comment of “This may be overkill, but it works on my machine”).
When to rewrite Git history? (beside “Don’t rewrite history once it is shared.”). Written by Drew De Ponte on his blog.
[The Ultimate Guide to] Git Commit Creation by Drew De Ponte on his blog.
How to Use Git Stash to Efficiently Manage Your Code by Okoro Emmanuel Nzube on freeCodeCamp.
Finding when a bug was fixed with git bisect in Julia Evans TILs (Today I Learned).
- Julia Evans has written a series of articles on Git, which were referenced in Git Rev News from Edition #103 to #111.
- She has also published two zines about Git: Oh shit, git! and How Git Works
Quick tip: Ignore commits in Git blame using a file (recommended name is .git-blame-ignore-revs) by Marijke Luttekes on her blog.
4 reasons you should use Git for productivity, even if you aren’t a developer by Adam Conway on XDA Developers blog.

Doomed Keys and Hidden Threats: The Scariest Secrets in Your Repositories by Gaetan Ferry and The Extent of Hardcoded Secrets: From Development to Production by Guillaume Valadon on GitGuardian Blog.

Git tools and sites

GitFourchette - The comfortable Git UI for Linux. Under development; you can currently install it with AppImage or from source. Written in Python, using the Qt UI (via PyQt6/PySide6) and pygit2. Under GPLv3 license.
Changesets is a tool to manage versioning and changelogs with a focus on multi-package repositories (monorepos). Written in TypeScript, under MIT license.
- For an explanation of the “monorepo” concept see What is a Monorepo? on monorepo.tools (this site was mentioned first in Git Rev News Edition #84).
Beachball: The Sunniest Semantic Version Bumper. Tool for automating npm publishing. Written in TypeScript, under MIT license.
git-sizer is a tool that computes various size metrics for a Git repository, flagging those that might cause problems. Written in Go, under MIT license.
- This tool was mentioned in passing in Git Rev News Edition #37.
git-remote-s3 is a library that enables you to use Amazon S3 as a git remote and as an LFS server.
It provides an implementation of a git remote-helper to use S3 (Amazon Simple Storage Service) as a serverless Git server, and of the git-lfs custom transfer to enable pushing LFS managed files to the same S3 bucket used as remote. Written in Python, under Apache 2.0 license.
PatchScope is a tool that annotates files and lines of diffs (patches) with their purpose and type, and performs statistical analysis on diffs and on the generated annotation data. It also includes a web app, displaying various data visualizations. Written in Python, under MIT license.
- Its README includes a list of similar tools and sites, many of which were mentioned here on Git Rev News.
Mergiraf is a syntax-aware git merge driver (and a mergiraf command line tool that helps solving merge conflicts) for a growing collection of programming languages and file formats. Adding a new language to Mergiraf is done in a declarative way. Written in Rust, under GPLv3 license.
- The author recommends using Mergiraf together with Difftastic, a structural diff tool that understands syntax, mentioned in Git Rev News Edition #86.
Diffdiff.net (formerly diff.so) is a web application that provides a fast, private way to compare two pieces of text in a “split diff”/”side diff” view, side by side with highlighting the text that is different from the text on the other side.

DiffLens - The Developer’s Diff Tool. Provides language-aware semantic diffs for GitHub Pull Requests, adding them as a comment to the pull request. Available as a GitHub app or a VS Code Extension. Proprietary tool, with 14 days free trial and demo. See above for possible alternatives.

Releases

Git 2.47.1
Git for Windows 2.47.1(1)
libgit2 1.8.4
Gerrit Code Review 3.10.3, 3.8.10, 3.9.8
GitHub Enterprise 3.15.0
GitLab 17.6.1, 17.6, 17.5.2
GitKraken 10.5.0
GitHub Desktop 3.4.9
Sourcetree 4.2.10, 4.2.9
Garden 1.9.1
Git Cola 4.9.0
git-credential-oauth 0.13.4
GitButler 0.14.0, 0.13.17
Tower for Windows 8.0, 8.1 (Release blog post)
Tower for Mac 12.3

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Ghanshyam Thakkar, Johannes Schindelin, Štěpán Němec, Bruno Brito and Toon Claes.

Git Rev News Edition 116 (October 31st, 2024)

chriscool — Thu, 31 Oct 2024 11:06:51 +0000

Git Rev News: Edition 116 (October 31st, 2024)

Welcome to the 116th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of September and October 2024.

Discussions

Support

fatal from submodule status --recursive when used with grep -q

Matt Liberty reported that when he tried using git submodule status --recursive | grep -q "^+" on a repo with a submodule, he got an error message like “fatal: failed to recurse into submodule XXX”, where XXX is the name of the submodule.

He expected no error message, no output and a 0 exit code from the whole command line as it should have succeeded. He guessed that Git didn’t like that grep when used with -q exits immediately (without printing anything) when there is a match.

Phillip Wood replied to Matt saying he assumed that grep’s exit broke the pipe between git and grep, so git received a SIGPIPE signal which killed it. Phillip suggested consuming the whole output from Git if the exit code from it was wanted.

Matt replied to Phillip that he was interested in the exit code from grep, not from git, and that Git shouldn’t output any error when its output is connected to a pipe that gets broken, in the same way as the yes command, for example, doesn’t output any error when piped to grep -q y.

Junio Hamano, the Git maintainer, also replied to Phillip’s first message that the error Git emitted in such a case wasn’t useful to the user.

Matt replied to Junio that he thought no error at all should be emitted as most Unix tools don’t output any error.

Then Phillip replied to Matt’s first reply to him. He asked if all Matt wanted was that git submodule status did not print any error message when it receives a SIGPIPE signal. Matt replied that he wanted both no error message and a 0 exit code from it.

Junio replied to Matt that it was reasonable to ask for no error message, but it should be OK if the exit code was related to the SIGPIPE message that the Git command received and that killed it. Junio used the example that even yes exited with code 130 when killed using the Control-C keys on a terminal.

The exit code associated with a signal is ‘128 + the signal number’, for example as the Control-C keys send a SIGINT signal, whose signal number is 2, processes killed this way should exit with code ‘128 + 2’, so 130.

Eric Sunshine replied to Junio that it wasn’t clear how the exit code from Git was important in the discussion as in the original command line, Git appears before the pipe, so its exit code might be lost.

Matt replied to Eric that the exit code mattered if the pipefail shell option was used.

Phillip replied to Matt suggesting he remap the exit code associated with SIGPIPE, which is 141 (128 + 13), to 0, if he was using pipefail but still wanted a 0 exit code. Phillip also gave an example shell function to help with that remapping, and sent a first version of a patch to fix the error message.

Junio reviewed that patch and found that it was unnecessarily including the “signal.h” system header.

Phillip fixed that issue in version 2 of the patch which was merged and part of Git v2.47.0.

Developer Spotlight: Chandra Pratap

Editor’s note: Just like in our previous edition, we return with another GSoC retrospective interview in this issue. We hope the reflections shared by GSoC students will provide an insightful perspective that benefits the community. As always, we welcome your thoughts and feedback!

Who are you and what do you do?

Hey! I am Chandra Pratap (prefer going by Chand) and I am an undergraduate student of Mathematics at SVNIT, Surat, India. I have a passion for everything computing and like to solve leetcode-styled problems in my free time or contribute to open-source software.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your GSoC project?

C was the first programming language that I learnt, and I wanted to try working on a non-trivial software project. I watched a YouTube video on open source and that’s where I got the idea of looking for open-source projects to contribute to. Git and VLC were the only open-source C-written software that I was familiar with and used in day-to-day life, so I decided to start contributing to Git out of the two. By the time GSoC came around, Git was the only open-source community that I was familiar with, so I decided to choose it as my GSoC organization.
How do you feel your contribution has impacted the Git community or the broader open-source ecosystem?

My project was about moving and improving reftable tests, so I think my contributions made life somewhat easier for other Git hackers, especially those who frequent the reftable sub-project. My project didn’t really affect any user-facing aspect of Git, so I don’t think it had a huge impact on the broader open-source ecosystem, besides the fact that it gained another lifelong contributor.
Is there any aspect of Git that you now see differently after having contributed to it?

Everything, to be honest. Working on and with Git for the duration of my project completely changed my mental model for the tool. Before GSoC, Git was a clunky tool reserved for software development work but post-Git, I know the most frequent commands like the back of my hand, and I’ve already used Git to version control many of my non-software files. I feel like I’ve learnt enough Git to last my entire career.
How do you balance your contributions with other responsibilities like work or school?

I had summer vacation for the entire duration of GSoC and no other work commitments, so I had no problems finding time for my GSoC project.
Can you share how GSoC helped enhance your technical and non-technical skills (like communication, project management, etc.)?

In terms of technical skills, I think my C and Git skills saw the biggest jump. I am a lot more comfortable working with those two tools than when I was pre-GSoC. Besides that, I’m a lot less scared of the command line now. In terms of non-technical skills, I believe I’ve gotten a lot better at composing mails and communicating with other professionals. I’ve learnt to write with the right amount of professionalism, so I don’t appear too uptight or too lax, the right way to respond to constructive feedback, how to time my schedule to fit with others’, especially those living in other parts of the globe, and how to ask good questions.
What was your biggest takeaway or learning from GSoC that you now apply regularly in your work?

I’d say the biggest takeaway from GSoC for me was that it is normal for everyone to face difficulties when trying to learn a new codebase, tool, etc, or even a different part of the same codebase. It is important to persevere and not be afraid of asking questions to achieve the desired results. Other than that, I’ve learnt a lot about good practices in software development, like appropriately splitting commits and writing good commit messages, that I subconsciously incorporate in my work now.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

The biggest challenge in contributing to Git was the initial phase of getting involved. I remember starting out working on a small patch for about 2 months with a lot of help from other contributors before it got accepted into Git’s upstream. After a few initial contributions, I grew more confident and could steadily find things to work on and produce acceptable results. The key to overcoming this challenge was to be persistent and patient, and not being afraid of asking silly questions.
Have you thought about mentoring new GSoC students?

I’m not sure about being a full-on mentor, but I’d love to co-mentor any future GSoC student(s) interested in working on the reftable project.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

The Git GUI tool. I believe that would make Git far more accessible than it currently is and get it incorporated in a lot more people’s day-to-day works.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The packed-refs format for refs seems redundant to me now that reftable is a core part of Git.
What is your favourite Git-related tool/library, outside of Git itself?

GitGitGadget was a lifesaver when I had just started contributing to Git, so that is probably my favourite Git related tool.
What is your toolbox for interacting with the mailing list and for development of Git?

I used Git’s send-email to send patches to the mailing list (especially the --compose and --annotate flags) and Gmail’s online client to convey non-patch mails. For developing Git, I used Vim as the editor on an Ubuntu machine and Git as the version control software (duh).
How do you envision your own involvement with Git or other open-source projects in the future?

I plan on making small contributions to Git from time to time, since I cannot find enough time for larger patches. Other than that, I’ll try to volunteer as a Git mentor for future GSoC or Outreachy cohorts. Regarding other open-source projects, I’ll try contributing to them when I learn a new technology and want a real-world experience.
What is your advice for people who want to start Git development? Where and how should they start?

Go through Git’s ‘My First Contribution tutorial’ for the initial setup and to get an idea of what’s it like to work on Git. Then work on a few ‘microprojects’ (more information on the Git Developer’s website) to dip your toes in the Git Development community. From there, you can figure out interesting stuff to work on by yourself.
Would you recommend other students or contributors to participate in the GSoC, or other mentoring programs, working on Git? Why? Do you have advice for them?

Yes. I believe that Git is a tool that every working professional can find useful regardless of whether they work in the software industry or not, and working on Git through an open-source program is an excellent way to get good at it in a short period of time. There’s also the added benefit of joining a large and active community of amazingly experienced developers who can teach you a lot about writing software, and the software development workflow in general.

I think the key to getting selected as a participant in GSoC or other mentoring programs is getting involved as early as possible. The more time you allow yourself to get familiar with Git’s codebase and development workflow, the easier it becomes to find an apt project and write a reasonable proposal for it. Also, the initial phase of contributions is the most difficult part of getting involved with an open-source project, so it is better to allow yourself ample time to tackle that initial hurdle.

Other News

Various

Highlights from Git 2.47 by Taylor Blau on GitHub Blog. Includes features like incremental multi-pack indexes, %(is-base:) atom for git for-each-ref (see also the Brooke Kuhlmann article, mentioned below), the new “Platform Support Policy” document, git mergetool directly supporting Visual Studio Code merge tool, and others.
What’s new in Git 2.47.0? by Justin Tobler on GitLab Blog. Highlights include init.defaultRefFormat configuration option that can be set to use reftable backend (see Beginner’s guide to the Git reftable format), init.defaultObjectFormat configuration option that can be set to sha256, git refs verify, and others.
Tower is running a Git GUIs User’s Survey for people who do not 100% of the time use Git in the terminal.

Light reading

How Typefully Uses Tower [Git GUI Client] to Conquer Social Media Publishing by Bruno Brito on Tower Blog.
Moving all our Python code to a monorepo: pytendi.
Bruno — An API Client Using Git to Fight for Developer Experience by Ryan Reynolds on Tower Blog.
Using Git as Your Personal To-Do List by Munem Prionto on DEV.to - more as a way of learning Git by the way of managing a TODO list, rather than for practical reasons.
- Contrast with Using Git to Manage Todos by Jezen Thomas (2015), mentioned in Git Rev News Edition #9, which is about using Git to help manage TODO or FIXME comments in the codebase (assuming that for example your IDE does not have a plugin for managing TODOs).
- One can also consider using a CLI tool that stores data in plain text files for managing TODOs, like Taskwarrior. Plain text files work well with Git.
Git For Each Ref by Brooke Kuhlmann in Alchemists Collective articles. Learn how to use this command to make use of references for information dumping, statistics, and much more. Included in this article is use of the new is-base field name recently added in Git 2.47.0.
Searching for and navigating Git commits by Alex Harri on his blog.
Why some of us like “interdiff” code review by Austin Seipp (a Gist). Describes problems with the UI of multi-commit GitHub Pull Requests for responding to reviewer comments by providing a new version of the patch series, and how git range-diff and interactive rebase can help with this task.
How I Review GitHub PRs by Benjamin Pollack on bitquabit.
Python PGP proposal poses packaging puzzles by Joe Brockmeier on LWN.net - Sigstore vs OpenPGP. Sigstore was mentioned in Git Rev News Edition #91 and #111.
A look at the aerc mail client by Joe Brockmeier on LWN.net.

Scientific papers

Tsukasa Yagi, Shinpei Hayashi: “Toward Interactive Optimization of Source Code Differences: An Empirical Study of Its Performance”, arXiv:2409.13590, with dataset at https://doi.org/10.5281/zenodo.13618978 (but no source code).
- It is based on a prior study: Nugroho, et al.: “How different are different diff algorithms in Git?: Use –histogram for code changes” (2019), https://doi.org/10.1007/s10664-019-09772-z

Git tools and sites

Reviewing git contributions via email (https://git-am.io/) is a companion piece to interactive guide on sending patches with git send-email (https://git-send-email.io/); the latter was mentioned in Git Rev News Edition #50 #68, and #92.
“Data Management” section of Awesome MLOps also includes tools related to versioning data like
- Dolt (Git Rev News #62),
- DVC (first mentioned in Git Rev News #42, then in #63, #64, #100, #107, and #113, among others),
- Dud, improving on DVC, but with narrowed scope,
- Intake (Git Rev News #96),
  - See also the discussion in issue #337 in the Intake repository: Data versioning/validation: Comparing Intake with DVC, Quilt and Great Expectations
- lakeFS (Git Rev News #78),
- Quilt / Quilt Data (Git Rev News #99).
git-task is a local-first task manager/bug tracker that stores everything within your git repository, and which can sync issues to/from GitHub or GitLab. Written in Rust, under MIT license.
Bruno is a fast and Git-friendly open-source API client, similar to Postman, Insomnia and similar tools. It stores collections directly in a folder on your filesystem in a plain text markup language, Bru.
- Compare with Simple Web Application Test (SWAT), web application oriented testing framework, with test plan stored as plain text files in specially named directories.

Releases

Git 2.47.0, 2.47.0-rc1
Git for Windows 2.47.0(2), 2.47.0(1), 2.47.0-rc1(1)
libgit2 1.8.4, 1.8.3
GitLab 17.5.1, 17.4.3, 17.3.6, 17.5, 17.4.2, 17.3.5, 17.2.9
Gerrit Code Review 3.10.2, 3.8.9, 3.9.7
GitHub Enterprise 3.14.2, 3.13.5, 3.12.10, 3.11.16
GitKraken 10.4.1, 10.4.0
GitHub Desktop 3.4.8, 3.4.7, 3.4.6
Garden 1.9.0, 1.8.0
git-credential-oauth 0.13.3
GitButler 0.13.8, 0.13.7, 0.13.6

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Chandra Pratap, Brooke Kuhlmann, Štěpán Němec and Brandon Pugh.

Git Rev News Edition 115 (September 30th, 2024)

chriscool — Mon, 30 Sep 2024 11:06:51 +0000

Git Rev News: Edition 115 (September 30th, 2024)

Welcome to the 115th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of August and September 2024.

Discussions

General

Git Merge 2024 conference and Contributor’s Summit 2024

The Git Merge conference happened on September 19th and 20th in Berlin, hosted by GitButler and GitHub.

The first day consisted of talks and an afterparty in the evening sponsored by GerritForge.

On the second day, there was the Contributor’s Summit in parallel with breakout unconference sessions.
Git participated in GSoC (Google Summer of Code) 2024

All the contributors have successfully passed their final evaluation and published a final report:
- Jialuo She worked on the Implement consistency check for refs project. He was mentored by Karthik Nayak and Patrick Steinhardt. The final report can be found on his website.
- Chandra Pratap worked on the Move and improve reftable tests in the unit testing framework project. He was mentored by Patrick Steinhardt and Christian Couder. The final report can be found on his website.
- Ghanshyam Thakkar worked on the Move existing tests to a unit testing framework project. He was mentored by Christian Couder and Kaartic Sivaraam. The final report can be found on his website.
Congratulations to the contributors and their mentors!
Git will participate in the next Outreachy round

Git applied to participate in the next Outreachy round from December 2024 to March 2025 and was accepted. Two projects are proposed:
- “Convert unit tests to use the clar testing framework” which will be mentored by Patrick Steinhardt and Phillip Wood.
- “Finish adding a ‘os-version’ capability to Git protocol v2” which will be mentored by Christian Couder.
See this Outreachy webpage for more information about the application process for contributors.

Reviews

[PATCH] tests: drop use of ‘tee’ that hides exit status

Junio Hamano, the Git maintainer, sent a patch removing uses of the tee command from test scripts. tee(1) is a shell command that duplicates its input to both its output and to one or more files. The issue was that in some test scripts it was used after a pipe to directly duplicate the output of a Git command, so using a format like:

git COMMAND OPTIONS... | tee FILE...

However, it’s not a good idea to use a pipe after a Git command because pipes discard the exit code of the command before them, so the standard (Unix) shell behaviour is that the exit code of the whole sequence is simply the exit code of the last command of a pipe sequence, here tee. In Git tests though, we wouldn’t want a test to pass if the Git command fails when it should succeed.

[For shell intimates: there are ways to override this default behaviour, such as the pipefail option, or named pipes, but there are a number of reasons, like shell portability and making it easy to understand small parts of the code, why Git developers try to avoid using those features in the Git codebase.]

As there was no reason to hide the exit code of the Git commands in the tests that used tee, Junio’s patch basically just replaced | tee with a simple > redirection.

Rubén Justo replied to Junio suggesting a wording improvement in the commit message, but otherwise agreeing with the patch.

Johannes Schindelin, alias Dscho, also replied to Junio saying that having something that duplicates the output of the Git command to standard output could still be useful for debugging, especially when dealing with CI failures. He showed an implementation of a redirect_and_show() helper function that could perhaps be used instead of tee, but agreed that it might be overkill and hoped that having more unit tests written in C could help.

Jeff King, alias Peff, replied to Dscho saying that a better help for debugging CI failures might be to have a way to automatically save the state of the test directory, called trash directory.tXXXX-YYYY where tXXXX-YYYY is related to the name of the test script.

Junio also replied to Dscho saying that a simple cat FILE instruction could be added after the lines where | tee was replaced with a redirection to make sure the Git command output appeared on standard output. Junio also agreed with Peff that saving the state of test directories would be best to debug CI failures.

A version of Junio’s patch taking into account the wording improvement suggested by Rubén was eventually merged.

Developer Spotlight: Jialuo She

Editor’s note: We’re starting a new initiative in Git Rev News where we interview recent GSoC/Outreachy students to get their reflections on completing their projects. Feel free to share any thoughts or feedback you might have!

Who are you and what do you do?

My name is Jialuo She. I find it quite challenging to select an English name for myself, so I decide to leave it as is. However, you can simply call me “Luo(/lwɔː/)”. I am currently employed at NVIDIA as a Tegra System Architect. In this role, I am responsible for developing the verification infrastructure for complex full-chip features, such as CPU-GPU cache coherency. So my daily job is unrelated to Git. In my spare time, I continue my GSoC work to implement consistency checks for refs.
How did you initially become interested in contributing to Git, and what motivated you to choose it as your GSoC project?

When I was a student, I read the book “Pro Git” to learn how to use Git in my daily development process. One day, I found a tutorial that teaches how to write a mini Git step by step, and I really appreciated the design of Git.

As I was approaching my graduate school graduation, I hoped to use the opportunity provided by GSoC to do something meaningful for the long term. Since I felt that I had an understanding of Git’s internal principles, believing that my chances of being selected would be much higher. When I saw the “Implement consistency check for refs” project, I became very interested and resolutely chose Git.
How do you balance your contributions with other responsibilities like work or school?

As a newcomer, contributing to Git can be particularly time-consuming due to unfamiliarity with the overall codebase. I would dedicate an evening to responding to review feedback, which forces me to think about how to make improvements, and then I would code over the weekend. Of course, if there were urgent situations at work or life, I would have to postpone my contributions to Git. I feel there’s no need to think about balancing because it happens naturally.
What was your biggest takeaway or learning from GSoC that you now apply regularly in your work?

After participating in GSoC, I begin to consider whether my commit sequence is clear and understandable when writing code at work. I also become more stringent with myself regarding commit messages, ensuring they clearly explain the background, motivation, and implementation details.
What was the biggest challenge you faced during your contributions to Git, and how did you overcome it?

When building the ref consistency check infrastructure, I encountered an exceptionally long review process that lasted about three months. It was quite frustrating because there was no positive feedback compared with other participants. Then I reflected on myself, wondering why I was always comparing myself to others instead of focusing on what I was doing. So, I adjusted my mindset.
Have you thought about mentoring new GSoC students?

If I have the opportunity and time, I would definitely mentor GSoC students. I am very grateful to my mentors, Patrick and Karthik, for introducing me to the Git community and enabling me to continue contributing after completing GSoC. I hope that one day I can also ignite the passion in others.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The write and read support for symlink symrefs.
What is your favorite Git-related tool/library, outside of Git itself?

I very much like the GitLens tool when using VSCode. By using this tool, I hardly use the bare git blame command.
What is your toolbox for interacting with the mailing list and for development of Git?

When reviewing patches, I will firstly use b4 or simply fetch the branch stored in Junio’s tree, and then I will see the diffs just in the VSCode. To reply to a patch, I download the raw email and use mutt to write contents. When sending patches, I still use mutt to make the environment as simple as possible to improve efficiency.

I develop Git using VSCode and the clangd language server. I generate the compile_commands.json file using compiledb make. I believe this is one of the best development approaches available today, offering excellent code suggestions, completions, and static analysis.
How do you envision your own involvement with Git or other open source projects in the future?

I hope to complete the implementation of all ref consistency checks. Additionally, I aim to further familiarize myself with the Git codebase related to refs, follow the development of the reftable backend, and participate in more reviews.
What is your advice for people who want to start Git development? Where and how should they start?

In my opinion, the barrier to starting contributions to Git is relatively high because Git doesn’t have something like “good first issue” labels. Therefore, I believe the best approach is to participate in mentoring programs or continue work from certain mentoring programs as a student.
Would you recommend other students or contributors to participate in the GSoC, or other mentoring programs, working on Git? Why? Do you have advice for them?

I highly recommend that students integrate into the Git community through mentoring programs. These programs provide basic ideas to help you get started and contribute to Git. Working on Git is an amazing experience, allowing you to be guided by many experienced contributors, improve your code quality standards, and enhance your communication skills.

As for advice to participants, I believe the most important thing is not to think of the project merely as a resume booster. Instead, let your passion shine through and stay at the community after mentoring programs.

Other News

Various

Radicle 1.0.
Radicle is a peer-to-peer, local-first code collaboration stack built on Git. Radicle was first mentioned in Git Rev News Edition #49, then in Edition #70, #86, and #110 - where one can find similar and related tools.
git-scm.com is now a static website by Johannes Schindelin on the Git mailing list.
Moving git.github.io, Git Developer Pages and Git Rev News’ website into git-scm.com is discussed in GitHub issue #729.

Light reading

Why GitHub Actually Won: How GitHub actually became the dominant force it is today, from one of its cofounders. Written by Scott Chacon on GitButler Blog.
Nice companion to various articles on Git history, like the latest A Git story: Not so fun this time in Git Rev News #113 - in #113 you can also find links to other editions with links to other retellings of the Git history.
Rethinking code reviews with stacked PRs on Aviator blog by Ankit Jain (also available on DEV.to, published by Ibrahim Salami. Aviator provides av, a CLI tool to help with managing stacked PRs on GitHub.
- Stacked Pull Requests, also under the name Stacked Diffs, were most recently mentioned in Git Rev News Edition #111, where you can find links to other editions with other articles, and to related tools.
- See also Stacked PRs CLI Product Comparison (Public) Google Sheet spreadsheet.
- Contrast Patterns for Managing Source Code Branches, which strongly recommends patterns that are best suited to Continuous Integration, first mentioned in Git Rev News Edition #63, and Ship / Show / Ask: A modern branching strategy, mentioned in Edition #79.
Git With Python HowTo: GitPython Tutorial And PyGit2 Tutorial by Marco Antonio Carcano on his blog ‘The grimoire of a modern Linux professional’.
Beyond “Commit” and “Push”: 5 Advanced Git Features You Should Know by Bruno Brito on GitTower Blog. Covers git-bisect, git-rerere, gitattributes, git-notes, and git-worktree.
Mastering Tower (Windows Edition) and Mastering Tower (Mac Edition) by Bruno Brito on GitTower Blog. Tower is a proprietary Git client for Mac and Windows, with 30-day free trial.
Git bisect run techniques by Victor Engmark on paperless.blog.
Semantic Versioning with GitVersion (GitFlow) by Raul Naupari on his blog; Featured on daily.dev, also available on DEV.to.
Host your own Radicle seed node by Eduard on Ed’s Site. Also available on DEV.to.
Creating a Git commit: The Hard Way (with low-level plumbing commands) by Aryan Ebrahimpour on Avestura’s Personal Website.
My Git cheatsheet - a list of some useful commands, as a cheatsheet or a simple reminder to keep and share. Written by Pierre-Yves Lapersonne on his French and English pylapp blog in the fediverse (write.as).

Git tools and sites

b4 is a tool created to make it easier for project developers and maintainers to use a distributed development workflow that relies on patches, e-mail and distribution lists for code contributions and review (like those used in Linux kernel development). This tool was first mentioned in Git Rev News Edition #61; you can find links to various articles and posts about this tool in Edition #61, #91, #95, #107 and #109. Written in Python, under GPL-2.0 license.
Phabricator.KDE.org is KDE’s desktop environment task management system. It was used for patch review and other functions in the past, but KDE has since transitioned to GitLab, at https://invent.kde.org. Bug tracking is done using https://bugs.kde.org. Phabricator is still used for task tracking by KDE until this functionality is migrated to GitLab.
- Phabricator is/was a suite of web-based development collaboration tools, which includes a code review tool called Differential, a repository browser called Diffusion, a change monitoring tool called Herald, a bug tracker called Maniphest, and a wiki called Phriction.
  Phabricator is no longer actively maintained by Phacility since June 1, 2021. This tool was mentioned in Git Rev News Edition #13. Written in PHP, under Apache 2.0 license.
- Phorge is a community-maintained fork of Phabricator, public since Sep 7, 2022. It seems to be actively developed.
nb-clean cleans Jupyter notebooks of cell execution counts, metadata, outputs, and (optionally) empty cells, preparing them for committing to version control. Written in Python, under short ISC license.
av (Aviator) is a command-line tool that helps you manage your stacked PRs on GitHub. Written in Go, under MIT license.
Stacked PRs CLI Product Comparison (Public) is a Google Sheet spreadsheet by Aviator, listing various stacked PR/stacked diff tools:
- ghstack in Python,
- gh-stack in Rust - no longer developed,
- git-branchless in Rust (mentioned in Git Rev News Edition #76, #90, #93, #98, and #106),
- git-branchstack in Python,
- git-chain in Rust,
- git-machete in Python
  - also available as a plugin for the IntelliJ Platform products,
- git-ps-rs - Git Patch Stack in Rust,
- git-series in Rust (first mentioned in Git Rev News Edition #18, with a link to the presentation in #19),
- git-stack in Rust,
- graphite-desktop (formerly graphite-cli) in JavaScript/TypeScript - no longer actively developed,
- Sapling SCM Git-compatible source control system by Facebook (mentioned in Git Rev News Edition #93),
- spr - Stacked Pull Requests on GitHub, in Go,
- Stacked Git (StGit) in Rust (mentioned in Git Rev News Edition #17, #21, and #74, and finally presented as a tool in #93).
degit is a CLI tool that makes copies of Git repositories faster than ordinary git clone. Supports GitHub, GitLab, Bitbucket, and Sourcehut (sr.ht). Written in JavaScript for Node.js, under MIT license.
GitVersion is a tool that generates a Semantic Version number based on your Git history. Available as Continuous Server pipeline, CLI tool, MSBuild task, and software library. Written in C#, under MIT license. Works on Windows, Linux, and Mac.
ugit: DIY Git in Python is a tutorial on Git internals, where you learn about how Git works on the inside by trying to implement (micro) Git in Python.

Releases

Git 2.47.0-rc0, 2.46.2, 2.46.1
Git for Windows 2.47.0-rc0(1), 2.46.2(1), 2.46.1(1)
GitHub Enterprise 3.14.1, 3.13.4, 3.12.9, 3.11.15, 3.10.17
GitLab 16.10.10, 16.9.11, 16.8.10, 16.7.10, 16.6.10, 16.5.10, 16.4.7, 16.3.9, 16.2.11, 16.1.8, 16.0.10, 17.4.1, 17.3.4, 17.2.8, 17.4, 17.3.3, 17.2.7, 17.1.8, 17.0.8, 16.11.10, 16.11.9, 17.0.7, 17.3.2, 17.2.5, 17.1.7
GitKraken 10.3.0
GitHub Desktop 3.4.5, 3.4.4
Garden 1.8.0
Git Cola 4.8.2
GitButler 0.12.26, 0.12.25

Credits

Git Rev News Edition 114 (August 31st, 2024)

chriscool — Sat, 31 Aug 2024 11:06:51 +0000

Git Rev News: Edition 114 (August 31st, 2024)

Welcome to the 114th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of July and August 2024.

Discussions

Reviews

[PATCH] ReviewingGuidelines: encourage positive reviews more

Junio Hamano, the Git maintainer, sent a patch to the mailing list which updated the ‘ReviewingGuidelines.txt’ documentation with the goal of encouraging positive reviews even more.

The ‘ReviewingGuidelines.txt’ documentation was created a few years ago by Victoria Dye to provide “consistent definitions for common review terminology” and to give advice to reviewers, in a similar way as the MyFirstContribution documentation gives advice to contributors.

The few paragraphs that Junio’s patch added said that positive reviews are highly encouraged, even when the author is a work colleague. They show that people other than the author(s) of the reviewed patches care about the issue that is addressed.

When writing positive reviews, reviewers should tell why they support the patches, and should show that they understand the issue and how the patches address it. They are also encouraged to describe how they understand complex parts of the patches.

Junio’s patch also adds a small paragraph saying that “uplifting feedback goes a long way towards encouraging contributors to participate more actively in the Git community.”

Eric Sunshine then replied to Junio pointing out a minor typo in his patch. Patrick Steinhardt replied to Junio too. He said that he had already guided some of his GitLab colleagues who review patches and suggested them to do what Junio describes.

Derrick Stolee, who prefers to be called Stolee, replied to Patrick agreeing with him and saying that it also helps to not have internal reviews for experienced contributors. He said that they used to have internal reviews at Microsoft but it was overly cautious and “loses the benefits of doing reviews in the open”.

Patrick replied to Stolee saying that GitLab also used to have an internal review, but it recently became optional and recommended only for people who are not yet familiar with the mailing list workflow.

Junio then sent a version 2 of the patch fixing small typos. Patrick reviewed this version and found it good, so it was later merged into the ‘master’ branch.

Other News

Various

GitLab now supports SHA256 repositories by John Cai on GitLab Blog (in Bulletin Board category).
Forgejo v8.0 is available.
- Forgejo is a self-hosted lightweight software forge, written in Go; nowadays a hard fork of Gitea (which in turn was based on Gogs). It was mentioned in passing in Git Rev News Edition #103, as one of the forges working on implementing the ForgeFed federation protocol for forge services.
Packt recently published the second edition of the “Mastering Git” book by Jakub Narębski, one of the Git Rev News editors. The book is available on PacktPub and on Amazon. The first edition of the book was mentioned in Git Rev News Edition #16; you can find the interview with Jakub Narębski in Edition #17.

Light reading

Different ways to use --patch in Git by Tekin Süleyman on his blog. It describes selectively stashing changes, selectively discarding changes, and selectively restoring changes. This article expands on the “interactively stage changes with --patch” advice in Git Tips you (Possibly) Didn’t Know You Needed.
Tracing the evolution of a Python function with git log by Joël Perras on his Nerderati blog. It shows a detailed example on using git log -L (and the diff=python gitattribute) to diagnose a real-life bug that was ostensibly caused by an upgrade to Authlib.
- This technique is also described in the See the History of a Method with git log -L article, mentioned in Git Rev News Edition #105.
Optimize your workflow with Git stash by Toon Claes (from GitLab) at MDN Blog.
Seriously, You Need to Learn Git by Lucy Linder on her blog (also available on DEV.to). The article defines various levels of Git knowledge, and explains how knowing Git might improve one’s development process.
Tips for creating merge commits by Brandon Pugh on his blog.
Back-dating Git commits based on file modification dates by Simon Willison in his TILs on Git (Today I’ve Learned).
- It was used by the author to create the 1991-WWW-NeXT-Implementation repository out of the archive of Tim Berner-Lee’s original code for the WorldWideWeb application for NeXT. This endeavor was described in a short blog post, 1991-WWW-NeXT-Implementation on GitHub.
Store Code Discussions in Git using Git Notes by Wouter de Jong on his blog. The article includes some code (in PHP) that uses the GitHub API to fetch the pull request comments and store them in notes (under the github-comments notes reference).
Attaching notes to git branches by Riccardo Bernardini on DEV.to. The article describes why this feature is useful and how git branch --edit-description and git notes fall short; this led to the creation of the git-branchnotes tool.
This developer tool is 40 years old: can it be improved? by Bill Harding (CEO at GitClear) on StackOverflow Blog. The article describes how GitClear’s “Commit Cruncher” diff algorithm works, which was created with the goal of making code reviews easier. Note that the Myers diff algorithm (created by Eugene Myers in his seminal work in 1986) is not the only one available in git diff: there are also minimal, patience and histogram diff algorithms available (via the --diff-algorithm option); this is not stated in the article.
How Different Are Different diff Algorithms in Git?: a paper with code by Yusuf Sulistyo Nugroho, Hideaki Hata, Kenichi Matsumoto from 2019.
Git Things: A grab bag of less frequently talked about git adjacent points by Alex Kladov (matklad) on his GitHub Pages-based blog, from 2023.
Unified Versus Split Diff: a discussion what is better for code reviews (and what the author uses) by Alex Kladov (matklad) on his GitHub Pages-based blog, from 2023.
How Does Git Store Files? — from a conceptual point of view. An article by by Alexis Määttä Vinkler on The Pragmatic Git blog, from 2023.

Code review antipatterns for the dark side developers, a joke article by Simon Tatham (don’t do any of the things described in this article).

Git tools and sites

The Pragmatic Git blog; note that some articles are paid members only. Powered by Ghost.
Carapace-bin provides argument completion for multiple CLI commands (full list including Git, git-extras, gh GitHub CLI, glab GitLab CLI, tea Gitea CLI, etc.), and works across multiple POSIX and non-POSIX shells. Details about the Git completion support can be found in issue #99. Written in Go under the MIT license.
Carapace-bin is a part of the Carapace multi-shell completion library and binary. A high-level overview of Carapace itself is available at https://pixi.carapace.sh.
git-random: quickly build random-content Git graphs with a specified shape. This is a tool that can work as an aid for learning and experimenting with Git. Source code available on GitHub. Written as a single-file Bash script under a custom CC BY-NC-SA 4.0 license with Hippocratic License v3 ethical requirements.
- The author mentions that this tool was inspired by seeing Lorna Jane Mitchell use Matthew J. McCullough’s generaterandomchanges in her talk “Advanced Git for Developers“ at Laracon EU 2015.
git-branchnotes is a command-line tool (that can be run as a git external command) that allows you to add notes to a branch and manage them. Written in Ruby.
w2vgrep - Semantic Grep is a command-line tool, with the interface similar to that of grep, that performs semantic searches on text input using word embeddings (word2vec). It’s designed to find semantically similar matches to the query, going beyond simple string matching. Supports multiple languages. Written in Go under the MIT license.
Collective Code Construction Contract (C4) is an evolution of the github.com Fork + Pull Model, aimed at providing an optimal collaboration model for free software projects.
- Compare with Ship / Show / Ask: A modern branching strategy model, mentioned in Git Rev News #79.

Releases

Gerrit Code Review 3.10.1, 3.8.8, 3.9.6
GitHub Enterprise 3.14.0, 3.13.3, 3.12.8, 3.11.14, 3.10.16
GitLab 17.3.1, 17.2.4, 17.1.6, 17.3, 17.2.2, 17.1.4, 17.0.6
GitKraken 10.2.0
GitHub Desktop 3.4.3
git-credential-oauth 0.13.2, 0.13.1

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Štěpán Němec, Brandon Pugh, Ralf Steube and Toon Claes.

Git Rev News Edition 113 (July 31st, 2024)

chriscool — Wed, 31 Jul 2024 11:06:51 +0000

Git Rev News: Edition 113 (July 31st, 2024)

Welcome to the 113th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of June and July 2024.

Discussions

General

[ANNOUNCE] Tickets available for Git Merge 2024

Taylor Blau announced that tickets for Git Merge 2024, Berlin, September 19th and 20th are now on sale. People who would like to come but need financial assistance with travel costs can contact the Git PLC or Scott Chacon directly.
[ANNOUNCE] Git Merge 2024 CFP deadline extended

Taylor Blau announced that the Git Merge 2024 CFP (Call For Proposals) limit has been extended by a week from August 1st to August 8th. So there are a few more days left to propose talks.
[ANNOUNCE] Berlin Git Meetup on August 14th, 6pm CEST

Patrick Steinhardt announced that some Git developers are trying to revive the Git user group in Berlin and will host their first session together with GitButler soon.

Support

[BUG] “git clean -df .” silently doesn’t delete folders with stale .nfs* files

Yuri reported that git clean -df ., which was supposed to delete a directory and all its contents, didn’t work when there were files named ‘.nfsXXXXXXXXXXX’ managed by NFS in that directory. He expected that git clean -df . would warn or error out when it cannot remove such a file, instead of ignoring the fact that it could not remove the file and the containing directory and terminating with a success exit code.

Junio Hamano, the Git maintainer, replied to Yuri saying that it was expected that directories that were not empty were not removed.

Yuri replied that he expected the ‘.nfsXXXXXXXXXXX’ files to be removed as they were untracked, that is, neither added nor part of the repo, and the command was expected to remove such untracked files.

Junio replied that the ‘.nfsXXXXXXXXXXX’ files were “a limitation” of NFS that applications, including Git, couldn’t and weren’t supposed to remove. He pointed to some documentation which explains what these special NFS files are, and that they originate from an NFS protocol based implementation strategy commonly known as “silly rename”.

Yuri replied that Git should still complain when it cannot remove such files, or that there should be a verbosity option that should make it complain in such cases.

Randall S. Becker replied to Yuri that he tried to reproduce the issue without using NFS and couldn’t. So he asked Yuri if he could share “a reproducible set of commands” and said that it was probably caused by NFS.

Junio replied to Randall and Yuri that removing a ‘.nfsXXXXXXXXXXX’ files under a real NFSv3 client would likely result in the file being automatically resurrected, and that failure to remove a file should indeed be reported as Git does when it cannot remove a regular file.

Yuri replied to Randall listing a series of instructions to reproduce the issue. He agreed that Git reported failures when it couldn’t remove a file because of “permissions and special flags reasons”, but he repeated that it should also do it in the case of such NFS files.

Randall replied to Yuri saying he thought that Git didn’t even see the NFS files. He asked if a second git clean -df . removed the NFS files and put new ones, with different names, in place.

Yuri replied that it wasn’t the case and there seemed to be a single NFS file.

Chris Torek then chimed into the discussion replying to Yuri. He explained in details how “NFS silly renames” work, and listed some cases which could result in NFS lying to Git by reporting that an unlink(2) operation succeeded when in fact the file was renamed but not deleted. In such a case Git could not report that it couldn’t remove a file. It could report that it couldn’t remove the containing directory though.

Chris finished his explanations saying “Anyway, that’s the OS view of this mess. I leave the work on Git itself to others. :-)”

Jeff King, alias Peff, replied to Yuri’s email that contained a series of instructions to reproduce the issue. He said he got the following warning when trying to reproduce:
```
warning: failed to remove xx/.nfs0000000002c8197f00000002: Device or resource busy
```
So Peff thought Git worked properly on his system and then communicated details of the OS and NFS mount he used.

Yuri replied by giving information about his system. He also said that when using rm -rf to remove the NFS file, he got a “Device or resource busy” error message, but not when using Git.

Randall replied to Peff that doing a self-mount to reproduce as Peff did was perhaps not the best, as the NFS client might be aware of the self-mount and things might not behave the same as in a regular mount.

Yuri suggested using a virtual machine to avoid a self-mount.

Gabor Gombas replied to Yuri reporting the results of his tests. He got a “Directory not empty” or a “Device or resource busy” error message when he used git clean -dfx, but he also got no error message when using git clean -df.

This led Yuri to reply that with -dfx Git indeed warns about NFS files on his machine, but with -df it doesn’t, because the NFS files are in the ignore list.

It is indeed expected that ignored files are not deleted and are just ignored without the -x option.

Developer Spotlight: Rubén Justo

Who are you and what do you do?

My name is Rubén, and that’s how it’s spelled correctly. However, some old friends call me Ruben because when we were kids changing names was a sign of friendship. Changing the accent from “ben” to “ru”, makes the letter ‘e’ lose its tilde when writing my name.

My $dayjob is not related to Git, but I use it quite often during the workday. Using it sometimes gives me an itch that I often can’t resist trying to scratch.
What would you name your most important contribution to Git?

I can’t think of any worth mentioning. But I’ll say something in the other direction; contributing to Git has not only meant solving some itches, but it has clearly made me improve my overall work style. I’m grateful for that.
What are you doing on the Git project these days, and why?

This can be read at any time: polishing up some itches that has come up for me or a colleague.

Lately, though, I find myself exploring more and more side issues that arise during iterations of the changes I was originally interested in.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’ll say a feasible one: something in Git that allows me to avoid writing shortcuts like @{-1}, @{1}, @{...

At least on my keyboard, it’s a pain to type @, {...}. And I tend to type those shortcuts a lot.

Perhaps too easy for the experts and they’ll have a lot of spare time during the year?
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I think that backwards compatibility is overrated most of the time. It’s usually a matter of getting on with it and time; sometimes a lot of time, I admit.

The steps being taken towards Git 3.0 seem very interesting to me [ref 1] [ref 2]. Perhaps there is an opportunity to do some breaking changes. I don’t have any in mind, though.
What is your favorite Git-related tool/library, outside of Git itself?

Definitely: tig.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Nope.
What is your toolbox for interacting with the mailing list and for development of Git?

To interact with the list, I mainly use lei, mutt and thunderbird in a rather makeshift way. Maybe someday I’ll finally configure git send-email.

In fact, more often than not, when I send a patch, I have the feeling that someone is going to come along and say: “Come on, Rubén. That user agent? Set up a decent environment to send this properly”.

To develop, I mainly use vanilla Vim.
What is your advice for people who want to start Git development? Where and how should they start?

Perhaps I would say that writing and reading code are not the most important skills in a project like Git. Empathy and the development of effective arguments to convey ideas or intentions are much more crucial.

Realizing and internalizing that, is a solid starting point, I think.
If there’s one tip you would like to share with other Git developers, what would it be?

Keep in mind that reviewing code is much harder than writing it, but writing a good message for the commit is even harder.

Other News

Various

Highlights from Git 2.46 by Taylor Blau on GitHub Blog. Those include pseudo-merge reachability bitmaps, subcommands in git-config (like git config list), an enhanced credential helper protocol, and improving the still experimental reftable support.
What’s new in Git 2.46.0? by Justin Tobler on GitLab Blog. Highlights include tooling to migrate reference backends (from files backend to reftables), symref update instructions for git update-ref --stdin, git config interface improvements (mentioned in the previous article linked), and bundle URI fixes.
Anyone can Access Deleted and Private Repository Data on GitHub via Cross Fork Object Reference (CFOR) from another [public] fork. Any code committed to a public repository may be accessible forever as long as there is at least one public fork of that repository. This is an intentional design decision by GitHub; see the documentation. There is though a separate fork network for public and for private versions of the same repository.
Posted on Truffle Security blog.
Debian debate over tag2upload reaches compromise by Joe Brockmeier on LWN.net. The tag2upload service promises a streamlined way for Debian developers using Git to upload packages to the Debian Archive.

Light reading

A Git story: Not so fun this time on Brachiosoft Blog. The title refers to the “Just for Fun” book, the 2001 autobiography of Linux kernel creator Linus Torvalds, and how the Git origin story wasn’t so much fun, at least for Linus. The article provides a list of references. Includes new material not seen in earlier retellings of the Git history, like the ones linked in Git Rev News Edition #2 (on 10 years of Git), Edition #52, Edition #62 (on 15 years of Git), Edition #105 and Edition #112 (among others).
Why Facebook doesn’t use Git by Greg Foster on Graphite Blog.
- See also Scaling Mercurial at Facebook, mentioned in Git Rev News Edition #24.
Pull requests via git push and a specially crafted pre-receive hook (and git-http-backend configured to allow anonymous push) that turns git push into series of patch emails. (Though this approach has some limitations.) Written by Steinar H. Gunderson on his blog.
- See also git-pr in the “Git tools and sites” section.
How I Use Git Worktrees by Alex Kladov (matklad) on his GitHub Pages-based blog. TL;DR: consider using worktrees not as a replacement for branches, but as a means to manage concurrency in your tasks (for example: view, work, review, fuzz, scratch).
Git autocorrect needs more marketing by Axel Navarro for Cloud(x); on DEV.to.
- See also thefuck, a command line application which corrects your previous console command (for example Git command) if you made an error (like typos in command name), and it didn’t do what you wanted; the tool was first mentioned in Git Rev News Edition #101.
commit messages are optional by Peter Schilling in schpet’s notebook (though for some of the mentioned uses, commits with empty commit messages are better replaced with git commit --fixup).
Git-ifying SVN: How I Brought Modern Version Control to an Age-Old System by Ione Souza Junior on his blog; also available on DEV.to as a last part of the mastering-git series. Another article from this series was mentioned in Git Rev News Edition #112.
Benchmarking the Modern Development Experience across Versioning Tools: S3, DVC, Git LFS, and XetHub by Ann Huang on XetHub blog.
- XetHub is a development platform for datasets and models, which automatically versions and tracks assets across the Machine Learning stack to guarantee reproducibility. Mentioned in passing in Git Rev News Edition #95.
- The comparison does not include DagsHub’s Direct Data Access / Data Streaming, which was announced in 2022. DagsHub, a web platform for storing, versioning and managing data (data hub), was first mentioned in Git Rev News Edition #72.
The visualization and analysis of git commit statistics for IT team leaders. by Aleksei Bakhirev (Responsive Crocodile) on DEV.to. Uses the Assayo tool written by the author for plots (see also the assayo.online webpage).
Some personal thought: beware of Goodhart’s law: “When a measure becomes a target, it ceases to be a good measure”. For examples from IT, see Joel on Software “Measurement” (2002).
Reorient GitHub Pull Requests Around Changesets from one giant mutable changeset, by Mitchell Hashimoto on his blog (2023).
A Note About Git Commit Messages (2008) by Tim Pope on tbaggery blog; it also explains some of the reasoning behind recommendations.

git good (My Hero Academia fanfiction, humor/horror) - Izuku’s quirk is Git, the version control software (some artistic license taken in order to make a good story). By Unknownlight. Available on Archive of Our Own, on FanFiction.net (not recommended by the author), and on SpaceBattles.
Summary:

Reality shattered like broken glass. The firmament that separated the real world from the eldritch beyond had broken. Two timelines had collided in the center of the street - an incongruous synthesis of two different chains of events. A building collapsed, and it did not. An explosion devastated the surroundings, and it did not. Screaming faces and laughs of joy overlapped each other as if viewed through a kaleidoscopic prism.

The crowd looked on in horror and awe. Who was responsible for tearing apart the fabric of reality?

Izuku groaned. ‘Great, another merge conflict’, he thought. ‘What a pain’.

Easy watching

I was wrong about git stash… (or rather, how one can use git worktree), by Philomatics on YouTube [5:18].

Git tools and sites

pico/git-pr (Patch Requests) is a new Git collaboration service, where you send and retrieve patches not via email but via SSH to a git-pr server:

# Contributor submits his/her changes:
git format-patch origin/main --stdout | ssh pr.pico.sh pr create test
# > Patch Request has been created (ID: 1)

# Owner can apply those changes via patch request:
ssh pr.pico.sh pr print 1 | git am -3

Can be self-hosted. Written in Go, MIT licensed.

eza is a modern replacement for the venerable file-listing command-line program ls. It knows about symlinks, extended attributes, and Git (like file status in Git repo, Git repo status, or ignoring files mentioned in .gitignore). Written in Rust, MIT licensed. See the documentation.
BlenderBIM is an add-on for detailed and data-rich OpenBIM (Building Information Modeling) with Blender. BlenderBIM supports tracking the development of your IFC files with Git (Industry Foundation Classes, or IFC, is an international standard for BIM). Note that merging requires the ifcmerge tool to be installed (ifcmerge is written in Perl and published under the GPLv3 license).
diff-pdf is a tool for visually comparing two PDFs which produces a PDF file with visually highlighted differences. Note that the repository states that the code is not being actively developed. Written in C++, GPLv2 licensed.
- See also pdf-diff in Python, CC0-1.0 licensed; another pdf-diff in Go, MIT licensed; and diff-pdf-visually in Python, dual licensed under both MIT License and Apache License, Version 2.0 - with a slightly different goal.
vdm: A General-Purpose Versioned-Dependency Manager is an alternative to e.g. git submodules for managing arbitrary external dependencies. Written in Go, MIT licensed.
- Contrast Gil (git links) tool to manage complex recursive repository dependencies with cross references and cycles, mentioned in Git Rev News Edition #110.
Bit-Booster is an Offline Commit Graph Drawing Tool, using HTML and SVG, generating graphs by pasting the result of running git log --all --date-order --pretty="%h|%p|%d" into a textarea.
- It is also an add-on for Atlassian Bitbucket Server.
- The webpage includes comparison with other various commit graph add-ons (2016).

How To Rotate is an open-source collection of API Key Rotation tutorials for different SaaS providers.
Act is a command line tool to run your GitHub Actions locally, using the Docker Engine API. Written in Go. Please look at the act user guide for more documentation.
- There is also Act runner, a runner for Gitea based on the Gitea fork of act.

Releases

Git 2.46.0, 2.46.0-rc2, 2.46.0-rc1, 2.46.0-rc0
Git for Windows 2.46.0(1), 2.46.0-rc2(1), 2.46.0-rc1(1), 2.46.0-rc0(1)
GitLab 17.2.1, 17.1.3, 17.0.5, 17.2, 17.1.2, 17.0.4, 16.11.6
GitHub Enterprise 3.13.2, 3.12.7, 3.11.13, 3.10.15, 3.9.18
GitKraken 10.1.1, 10.1.0
Garden 1.7.0
Git Cola 4.8.1
git-credential-oauth 0.13.0

Credits

Git Rev News Edition 112 (June 30th, 2024)

chriscool — Sun, 30 Jun 2024 11:06:51 +0000

Git Rev News: Edition 112 (June 30th, 2024)

Welcome to the 112th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of May and June 2024.

Discussions

Reviews

[RFC PATCH] docs: document upcoming breaking changes

Patrick Steinhardt sent an RFC patch to the mailing list that created a new “UpcomingBreakingChanges.md” document. The goal of the document was to inform users and developers of deprecations and breaking changes, and to encourage discussion of the direction of the project regarding these topics in advance.

Patrick noted that the changes listed in the document, along with links to mailing list threads where they had been discussed, were a work in progress with controversial and missing items, and that he didn’t want to push for a Git 3.0 release with the listed changes soon.

The idea for that new document had been discussed previously in a thread about a patch series from Patrick that introduced subcommands like get, set, etc, in git config. In that thread, after Patrick asked if we wanted to introduce a document to keep track of upcoming removals for a potential Git 3.0 release, Junio Hamano, the Git maintainer, replied to Patrick that in a few of his “What’s cooking” emails before the Git 2.44.0 release, he had written:

It may not be a bad idea to reflect on what technical debt and UI warts we have accumulated so far to see if we have enough of them to start planning for a breaking Git 3.0 release (or, of course, keep incrementally improve the system, which is much more preferable – continuity and stability is good).

So Junio was happy that “somebody has bit it ;-)” and suggested a number of topics that could be added to the document Patrick wanted to create. This started a discussion about the possibility of deprecating some features, such as the restore, switch, submodules and worktrees subcommands.

In the RFC patch to add the document, Patrick mentioned some of the topics suggested by Junio, but not others that seemed controversial in the previous discussion.

Johannes Schindelin, alias Dscho, replied to Patrick’s RFC patch saying he loved it. Dscho also gave his opinion about the topics, and suggested to deprecate or remove additional rarely used features.

Junio replied to Patrick’s patch suggesting to add features that we don’t want to drop and why, and to mention that we deprecate but, for backward compatibility, rarely remove old ways to do things. Patrick agreed to Junio’s suggestion and proposed a “superseded” section for the features we don’t want to drop.

Dragan Simic, who had participated in the discussions of the preceding git config thread, repeated that he didn’t want to see any of git restore, git switch or git checkout deprecated, which Patrick agreed shouldn’t be done.

Phillip Wood, replying to Patrick’s patch, asked if the document should track the progress of some unfinished work, like the config based hooks implementation. Patrick said he was planning on creating a separate document for long running projects, projects already discussed, and also small or micro projects, with the additional intent to help newcomers looking for something to work on.

Justin Tobler also replied to Patrick’s patch suggesting adding the removal of double dot and triple dot syntax (“..” and “…”) from git diff to the document. This was discussed by Junio and Patrick but, as it would need a lot more work, Patrick decided to not add it to the document for now.

Patrick then sent a version 2 of his patch adding a section about features “that are not to be deprecated” and proposing some further deprecations, while withdrawing the $GITDIR/hooks directory deprecation proposal.

Karthik Nayak replied to the patch version 2, listing a number of commands not mentioned in the document that do similar things, which might indicate that some of them could be deprecated too. Patrick, Junio and Dragan discussed these commands, but decided that only git pickaxe, which is an alias for git blame, could be removed for now.

So Patrick sent a version 3 of his patch, which only added the removal of git pickaxe.

Junio replied to this version 3 with a lot of comments to discuss how each item was justified and how we could improve on justifying items in general. Patrick then agreed on ways to improve the document.

Patrick sent a version 4 where the single patch had been broken down into 4 patches. In the process a lot of the proposed deprecations from the previous version were removed and the document name was changed from “UpcomingBreakingChanges.md” to “BreakingChanges.md” as some changes listed in the “Superseded features that will not be deprecated” section should not be considered upcoming.

The goal was to introduce the document in a skeletal form in the first patch and then add only one item to each of the three sections in the following patches. This way each of the last 3 patches should be an example of how other items should later be added to the document.

Junio, Patrick and Todd Zullinger then discussed relatively small improvements to the form and content of the document.

Patrick sent a version 5 of the patch series where the main change was that the document was converted to AsciiDoc instead of Markdown and renamed from “BreakingChanges.md” to “BreakingChanges.txt” for format compatibility with most other documents in the codebase.

Junio, Phillip Wood and Patrick discussed other small improvements, which Patrick integrated into version 6 of the patch series.

Junio then suggested a few more small improvements, which Patrick finally integrated into version 7 of the patch series, which was later merged into the ‘master’ branch.

Other News

Light reading

BitKeeper, Linux, and licensing disputes: How Linus wrote Git in 14 days by Nicholas Yan on Graphite Blog. See also, among others, GitHistory page in the archives of Git SCM Wiki, which was mentioned in Git Rev News Edition #105, and other links that were mentioned in that edition.
Git Workflows for API Technical Writers by James Higginbotham on Bump.sh. Mentions Bump.sh, an API doc platform for tech writers and engineers, at the end of the article.
What is Git? Our beginner’s guide to version control and Top 12 Git commands every developer must know by Kedasha Kerr on GitHub Blog. This blog post accompanies the GitHub for Beginners series (YouTube playlist).
Stop Wasting Hours! Git Bisect: Your Ultimate Bug Hunting Tool by Ione Souza Junior on his blog; also available on DEV.to as a part of mastering-git series.
The Magic of Git Stash: How It Saved My Day by waqaryounis7564 on DEV.to.
Prevent Hidden Merge Conflicts by Shinnigami on DEV.to; but note that the described solutions might warrant some more thought (linearizing history by requiring rebase instead of merge to integrate changes versus requiring branch to be up to date before merging), and are not the only possible solutions (for example: post-merge checks).
“Good Commit” vs “Your Commit”: How to Write a Perfect Git Commit Message by Safdar Ali on DEV.to.
- Compare the Conventional Commits specification, first mentioned in Git Rev News Edition #52, and Gitmoji, first mentioned in Git Rev News Edition #47.
Ten Things You Didn’t Know Git And GitHub Could Do by Owen Ou on Owen Ou’s blog (2012).
Versioning FreeCAD files with git (FreeCAD files are zip archives containing text documents) by Dante Catalfamo on lambda.cx blog (2021).

Programming in Unison by Daroc Alden on LWN.net (free subscriber link). Unison is an MIT-licensed programming language, where programs are stored in an append-only, content-addressed database (though still displayed to the user for editing as text, using the editor of their choice)… just like information about project versions is stored in Git.

Git tools and sites

setuptools-scm is a tool that extracts Python package versions from git or hg metadata instead of declaring them as the version argument or in an SCM managed file. Additionally, it provides setuptools with a list of files that are managed by the SCM (i.e. it automatically adds all of the SCM-managed files to the sdist). Unwanted files must be excluded via MANIFEST.in. The preferred way to configure setuptools-scm is via pyproject.toml.
The latest version and the stable version documentation are available on Read the Docs.
piku, which was inspired by dokku, allows you to do git push deployments to your own servers, no matter how small they are. An open source PaaS (Platform as a Service) alternative to services such as Heroku. Written in Python.
gitchangelog is a tool that creates a changelog from git log history. Written in Python; no longer actively developed (version 3.0.4 is from 2018).
- Compare with for example git-cliff changelog generator, mentioned in Git Rev News Edition #108.
git-open-remote is a shell script by masukomi to open the web page(s) for the repo’s remote(s). With this script you can simply cd into a git repo and type git open-remote. Requires open or xdg-open (aliased or linked to open) to open the web browser, and charm gum to implement the selection UI when the Git repo has more than one remote.
Git EOL Conversion Diagram for checkout as Gist providing an SVG version and an editable version on Mindmup, by Martin Leduc (@DecimalTurn).

Releases

Git 2.45.2 and friends to unbreak “git lfs” and others
Git for Windows 2.45.2(1)
GitHub Enterprise 3.13.0, 3.12.5, 3.11.11, 3.10.13, 3.9.16
GitLab 17.1.1, 17.0.3, 16.11.5, 17.1, 17.0.2, 16.11.4, 16.10.7
GitKraken 10.0.2
GitHub Desktop 3.4.2, 3.4.1
Tower for Mac 12.0 (BETA) — Release blog post
Garden 1.7.0, 1.6.0
Git-Cola 4.8.0
git-credential-oauth 0.12.1, 0.12.0

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Štěpán Němec, Bruno Brito, David Aguilar, Brandon Pugh and Dragan Simic.

Git Rev News Edition 111 (May 31st, 2024)

chriscool — Fri, 31 May 2024 11:06:51 +0000

Git Rev News: Edition 111 (May 31st, 2024)

Welcome to the 111th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of April and May 2024.

Discussions

General

[GSoC] Welcoming our 2024 contributors and thanking our applicants

The Git project was accepted in the Google Summer of Code (GSoC) this year again, and 3 applicants were selected:
- Jialuo She will work on the “Implement consistency check for refs” project mentored by Karthik Nayak and Patrick Steinhardt. He already started posting on his blog, and will push his work to his Git repo.
- Ghanshyam Thakkar will work on the “Move existing tests to a unit testing framework” project mentored by Kaartic Sivaraam and Christian Couder. He already started posting on his blog, and will push his work to his Git repo.
- Chandra Pratap will work on the “Move and improve reftable tests in the unit testing framework” project mentored by Patrick Steinhardt and Christian Couder. He already started posting on his blog, and will push his work to his Git repo.
Congratulations to them, and thanks a lot to all the applicants who worked on Git and submitted proposals! It was tough to choose from multiple potential contributors, all of them good in their own respect.
Git Merge conference and Contributor’s Summit

Taylor Blau from GitHub announced that Git Merge 2024 is happening in-person on September 19th and 20th in Berlin. It is being co-hosted by GitHub and GitButler.

The talks are scheduled on September 19th and the birds of a feather are scheduled on September 20th. Registration is yet to open.

The announcement welcomes calls for proposals, ideas on the format, topics for discussions, venue setup, and applications for financial assistance.

Reviews

[PATCH 0/3] color: add support for 12-bit RGB colors

Beat Bolli sent a patch series consisting of 3 patches to add 12 bit RGB color support to the color parsing code. That code is used especially when parsing configuration files, as a lot of configuration options allow users to customize how Git colorizes its output.

Before Beat’s patch series, the code supported the following:
- fixed strings, like normal, blue, red, etc,
- 256-color-modes from the terminal, like [1;38;5;254;48;5;255m , and
- 24-bit color values in the form #RRGGBB.
With Beat’s patch, it also supports 12-bit colors in the form #RGB, where in both the 24-bit and 12-bit forms, R, G and B are hexadecimal digits for the red, green and blue components of the color respectively.

The first patch in the series fixed a typo. The second patch added tests for invalid non-hexadecimal characters in #RRGGBB values.

The last patch added support for the #RGB form and mentioned in its commit message that such a shortened 12 bit form is already supported in Cascading Style Sheets (CSS). When used in CSS, each of the hexadecimal digits in this form is duplicated to convert the color to 24 bits, and the same duplication is performed in Beat’s patch. For example #f1b specifies the same color as #ff11bb.

Junio Hamano, the Git maintainer, replied to Beat’s third patch saying that it looked good. Junio noticed that a wrong #0xFF0000 value in a code comment was converted to the right #FF0000 value by removing Ox. He wondered if there were instances of the same mistake in our documentation. Beat replied that it was the only place he found such a mistake.

Taylor Blau then reviewed the patch series and said it looked “very nice”. Jeff King, alias Peff, also reviewed Beat’s series and commented on the third patch. Looking at the tests that checked the rejection of invalid values, Peff wondered what would happen if values like “#1”, “#12”, “#1234” were passed. Junio replied to Peff that such values would be worth covering in the tests but doing that in a separate cleanup patch outside this series would be fine.

Then Junio replied to himself and suggested adding such tests in the second patch of the series which already added tests for invalid values. Junio even sent a ‘fixup!’ patch to add these tests to the second patch. Peff replied that this ‘fixup!’ patch looked good.

Beat then sent a version 2 of his series that incorporated Junio’s patch. Both Junio and Peff approved of it, so it was later merged into the ‘master’ branch.

Developer Spotlight: Beat Bolli

Who are you and what do you do?

I’m a software engineer currently working in an Integration Engineer role for the Swiss government. When I’m not coding, I read, ride any of my three bikes or play the guitar or electric bass.
What would you name your most important contribution to Git?

I’m more a drive-by contributor. There are no big issues that I work on. For example, my very first commit was “just” a spelling correction.

The biggest contribution in terms of the number of commits was a cleanup of the test scripts that eliminated redundant processes in long pipelines.

Other topics that come to mind are the strict ISO date format, the “copy commit reference” menu item in gitk, and some cleanups to get a warning-free compile with -pedantic.
What are you doing on the Git project these days, and why?

As explained in the previous answer, I mostly see small things that I try to improve, like recently adding the 12-bit RGB color format.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Honestly, I’m pretty content with the state of Git. I’ve been using Git since 2009 and I guess I got used to its idiosyncrasies (but see the next question!).
If you could remove something from Git without worrying about backwards compatibility, what would it be?

There are too many different options and/or subcommands to remove things. Compare git remote remove, git branch (-d/-D), git rm (for files). I understand that these are different situations but from time to time I have to really think about which is the right syntax in a given case.
What is your favorite Git-related tool/library, outside of Git itself?

First, I’m a fan of the command line, so Git itself does over 80% of what I need. Next up are tig and vim-fugitive. I also use a comprehensive set of Git-related shell aliases that improve my efficiency.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Nothing out of the ordinary, but then I’m old-school and have no problems with an email-based workflow. My first commits were accepted without much fanfare, and this encouraged me to continue to submit things.
What is your toolbox for interacting with the mailing list and for development of Git?

I follow the mailing list on lore.kernel.org, and have also subscribed to the NNTP feed in Thunderbird. For submitting patches I have configured a few send-email options, probably like everyone else who contributes. I do most of my development on a Mac mini in iTerm2 and Vim.
What is your advice for people who want to start Git development? Where and how should they start?

First, don’t think you’re not good enough. By following SubmittingPatches and the rest of the beginner’s documentation, everyone can contribute. I experience the “mood” on the mailing list as very supportive and helpful.
If there’s one tip you would like to share with other Git developers, what would it be?

Just a tiny pet peeve of mine: sizeof is not a function 😉

Other News

Various

Securing Git: Addressing 5 new vulnerabilities fixed in v2.45.1, by Johannes Schindelin on GitHub Blog. The main theme of fixes in v2.45.1 is to improve the security of cloning Git repositories.

Light reading

A beginner’s guide to the Git reftable format (available since the release of Git 2.45.0). Article by Patrick Steinhardt on GitLab Blog.
Julia Evans has just published her new Git zine, “How Git Works”. She counted that she apparently wrote 28,000 words of blog posts while writing the zine. These posts were covered here, starting from Git Rev News Edition #103, and continuing, edition after edition, until the previous edition #110.
As a companion to this zine, there is a little git cheat sheet (PDF) freely available.
- Julia Evans had also published the “Oh Shit, Git” zine in 2018; as she describes: “Oh Shit, Git” is about how to get out of Git messes, while “How Git Works” explains why those messes happen in the first place.
- The Oh Shit, Git!?! website by Katie Sylor-Miller was first mentioned in Git Rev News Edition #19.
Securing Git repositories with gittuf by Joe Brockmeier on LWN.net is a report of a talk by Aditya Sirish A Yelgundhalli and Billy Lynch at Open Source Summit North America (OSSNA). The video of the talk is available on YouTube. Gittuf was mentioned in Git Rev News Edition #104.
Clone arbitrary single Git commit by Sebastian Pipping on Hartwork Blog. Inspired by GitHub Action actions/checkout.
Reverting File Changes in Git: A Comprehensive Guide by Geoffrey Kim on DEV.to.
What is Git? GitHub beginner’s guide to version control by Kedasha Kerr on GitHub Blog.
Signed Git commits with Sigstore, Gitsign and OpenID Connect (OIDC) by James Healy on Buildkite Blog. Sigstore and Gitsign tools for keyless Git signing were both mentioned in Git Rev News Edition #91.
Understanding the Stacked Pull Requests Workflow by Bruno Brito on Tower’s blog. There have been various approaches to adding stacks to Git workflows:
- Stacked Git (aka StGit) was mentioned in Git Rev News Edition #17, #21, and #74, and finally presented as a tool in #93.
- Stacked diffs were discussed in Stacked Diffs Versus Pull Requests (mentioned in Git Rev News Edition #44) and Stacked Diffs (and why you should know about them) (mentioned in #105).
- Working with stacked branches was mentioned in Git Rev News Edition #93.
How short can Git abbreviate? by Josh Stone on his WordPress-based blog (2013).

Easy watching

Securing Git Repositories with Gittuf - Aditya Sirish A Yelgundhalli, New York University & Billy Lynch, Chainguard. A 30 minute long video on The Linux Foundation channel on YouTube.

Git tools and sites

KSDB is the LWN.net kernel source database, a site which can answer a wide range of questions about the Linux kernel’s development history.
The Kernel.org Transparency Log Monitor webpage is a monitor of the kernel.org transparency log for git-receive operations. Among others, it tracks signed pushes (compare with gittuf). Runs kernel.org-git-verifier.
- There is also the Gitolite transparency log, with git-receive operations published at the transparency-logs/gitolite/git repositories in the public-inbox v2 format. Gitolite was first mentioned in Git Rev News Edition #17 and #22.
Sigstore Rekor is meant to provide an immutable tamper resistant ledger of metadata generated within a software project’s supply chain. It enables software maintainers and build systems to record and query signed metadata. Can be run as part of Sigstore or on its own.
Quickhook is a Git hook runner designed for speed. Written in Go.
etckeeper is a collection of tools to let /etc be stored in a Git repository, and use Git to review or revert changes that were made to /etc. Written as shell scripts (with some plugins in Python).
Dangit, Git!?! has the same contents, only without swears, as the Oh Shit, Git!?! website (first mentioned in Git Rev News Edition #19).

Releases

Git 2.45.1 and friends (2.44.1, 2.43.4, 2.42.2, 2.41.1, 2.40.2, and 2.39.4)
Git for Windows 2.45.1(1)
libgit2 1.8.1
GitLab 17.0.1, 16.11.3, 16.10.6, 17.0, 16.9.8, 16.11.2, 16.10.5, 16.9.7
Gerrit Code Review 3.10.0, 3.7.9, 3.8.6, 3.9.5
GitHub Enterprise 3.12.4, 3.11.10, 3.10.12, 3.9.15, 3.13.0, 3.12.3, 3.11.9, 3.10.11, 3.9.14
GitKraken 10.0.1, 10.0.0
GitHub Desktop 3.4.0, 3.3.18, 3.3.17, 3.3.16, 3.3.15
TortoiseGit 2.16.0
Git Cola 4.7.1
Garden 1.5.0
Tower for Mac 11.0 (blog post)
Tower for Windows 7.0
tig 2.5.10
git-credential-oauth 0.11.3

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Beat Bolli, Sven Strickroth, David Aguilar, Bruno Brito and Štěpán Němec.

Git Rev News Edition 110 (April 30th, 2024)

chriscool — Tue, 30 Apr 2024 11:06:51 +0000

Git Rev News: Edition 110 (April 30th, 2024)

Welcome to the 110th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of March and April 2024.

Discussions

General

What’s cooking in git.git (Mar 2024, #05; Tue, 19)

In March, Junio Hamano, the Git maintainer, sent one of the usual “What’s cooking in git.git” emails that describe the current state of the patch series that might be merged into the development branches (mostly “master”, “next”, and “seen”).

The patch series are listed in these emails along with some related information in a custom format, including the following elements:
- a title line, for example:
- bl/cherry-pick-empty (2024-03-11) 7 commits
where bl are the initials of the author, and cherry-pick-empty the series title,
- a patch list, for example:
- cherry-pick: add --empty for more robust redundant commit handling
- cherry-pick: enforce --keep-redundant-commits incompatibility
- sequencer: do not require allow_empty for redundant commit options
- sequencer: treat error reading HEAD as unborn branch
- rebase: update --empty=ask to --empty=stop
- docs: clean up --empty formatting in git-rebase (1) and git-am (1)
- docs: address inaccurate --empty default with --exec
- a description, for example:
“cherry-pick” told to keep redundant commits needs to be allowed to create empty commits to do its job, but it required the user to give the --allow-empty option, which was unnecessary. Its UI has also been tweaked a bit.
- a status, for example:
Comments?
- a source, for example:
source: 20240119060721.3734775-2-brianmlyles@gmail.com

Some of the above elements, like the description, are also automatically used to create the release notes that Junio prepares and sends when he creates a new release.

Brian Lyles replied to Junio that the description of the patch series used as an example above, which Brian had sent, was “a little out-of-date”. He suggested a different wording for it, and said that he was going to send a version 4 of his patch series.

Junio said that the wording suggestion for the description was very much appreciated, and wondered if the project could adopt a better workflow where contributors could write a short description at the top of the cover letter of their patch series and if that description could then be picked up automatically by some tools to appear in Junio’s “What’s cooking in git.git” emails.

Brian Lyles agreed that improving the process could be a good idea. He mentioned a strategy used by other projects, namely adding an entry in a “CHANGELOG.NEXT.md” file for each important commit. At release time, all the entries in that file would be moved into a standard “CHANGELOG.md” file. He then showed how the entry in the “CHANGELOG.NEXT.md” file would look like for his series as an example.

Junio replied by summarizing the current process related to these descriptions and pointing to the “Documentation/howto/maintain-git.adoc” file, which describes his workflow and says that maintaining these topic descriptions is his responsibility as the project maintainer. He then mentioned some downsides of giving that responsibility to the patch series authors.

One downside is that the description might be harder to read because the authors “inevitably are biased by the importance of their own work ;-)”. Another one is that the description might not be as consistent as when they are all written by the same person. Coming up with some description is also “a good opportunity” for the maintainer to find what is still unclear after reading the patches and the cover letter. Junio agreed that “the distribution of burden is certainly attractive” though.

Brian replied that he thought the author should still write something and that at least he was willing to do it. He also suggested having guidelines, like for commit messages, to help authors and reviewers standardize the style of these descriptions.

In the meantime, in a separate email, Junio also pointed out that a “CHANGELOG.NEXT.md” file would make merges more difficult compared to having the description in the cover letter.

To that Brian agreed, and proposed writing a patch to the “Documentation/SubmittingPatches” file to document that the description can be written in the cover letter.

Junio replied by proposing a patch to that file himself. Brian commented that the description might need “some specific heading, phrase, or other structured text” to mark it appropriately, making it easy to notice and extract.

Dragan Simic joined the discussion saying that writing the description should not be a strict requirement and then agreed with Junio’s patch. Max Gautier also chimed in, agreeing with Brian and Dragan about using a format to mark the description. Dragan replied that adding an example of such a formatted description in the patch Junio suggested would be good.

Junio replied to Brian that he preferred starting “with a lightweight process that does not burden participants with too much red tape”, so something like “When the first paragraph of the message looks like an entry in the Release Notes, it is used as such”, as he thought that the Release Notes style was “distinct enough” as to “not require any further marking”.

As Junio’s patch was then merged, it’s now officially possible to write a short description in patches or cover letters. This description might then be used as-is in the “What’s cooking in git.git” emails and in the release notes.

Other News

Various

Highlights from Git 2.45 by Taylor Blau on GitHub Blog.
What’s new in Git 2.45.0? by Patrick Steinhardt on GitLab Blog.
Adam Johnson’s book “Boost Your Git DX” has been updated with ten new pages of content. This book was mentioned in Git Rev News Edition #104.

Light reading

Julia Evans continues her series of blog posts about Git, preparing for a new Git zine, with Notes on git’s error messages. There are also Some Git poll results (which are, as admitted by the author, highly unscientific, and might not be representative). The first entry in this series of blog posts can be found in Git Rev News Edition #103, and it continues since, edition after edition so far.
Modern Git Commands and Features You Should Be Using by Martin Heinz on his blog. The list includes git switch, git restore, git sparse-checkout, git worktree, and (not new) git bisect.
Learn Git Fundamentals – A Handbook on Day-to-Day Development Tasks by Samyak Jain on freeCodeCamp.
Navigating the Stormy Waters of Git Merge Conflicts: A Guide for basic git conflicts by Jomagene for KADEA ACADEMY on DEV.to.
The guide to Git I never had. under Philip Miglinci’s byline, as Glasskube’s guide to Git (also on DEV.to, by Jake Page for Glasskube).
How to get somebody fired using Git (or: how to NOT use Git), by Mauro Accorinti on DEV.to.
What Happens on GitLab When You do git push? by Li Zhennan, on the personal blog.
Radicle: peer-to-peer collaboration with Git, an article by Lars Wirzenius on LWN.net.
- Radicle was first mentioned in Git Rev News Edition #49, then in Edition #70. There was also an article about Radicle from The New Stack in Git Rev News Edition #86.
- Compare with ForgeFed (formerly GitPub), a federation protocol for software forges, mentioned in Git Rev News Edition #69.
- There is also gitstr (git str), a tool to send and receive Git patches over Nostr, using NIP-34 (mentioned in Git Rev News Edition #109), and git-ssb (see the git-ssb-intro guide), a decentralized Git repo hosting and issue tracking on Secure-ScuttleButt (SSB) (mentioned in Git Rev News Edition #26 and #40).
Git as debugging tool by Lucas Seiki Oshiro on his GitHub Pages-powered personal blog (2023).

Easy watching

re:bass by Dylan Beattie [4:34]. If Git was music, what would it sound like? An original composition inspired by the Git version control system.

Git tools and sites

git bisect-find is a simple command to find where to start your bisection. Written in Rust.
- See also Announcing git bisect-find by Kevin Cox on his blog.
git-cz is a command-line tool to help you make semantic Git commits. Written in JavaScript for Node.js. Can be installed standalone, or with Commitizen (which was mentioned in Git Rev News Edition #72). Has non-interactive mode; is configurable (for example turning off emoji).
ydiff is a term based tool to view colored, incremental diff in a version controlled workspace (supports Git, Mercurial, Perforce and Subversion so far) or from stdin, with side by side (similar to diff -y) and auto pager support. Written in Python. (Its cdiff fork appears to be unmaintained.)
gws is a text user interface colorful helper to manage workspaces composed of Git repositories. Written in Bash.
Giftless (GitHub repo) is a Python implementation of a Git LFS Server. It is designed with flexibility in mind, to allow pluggable storage backends, transfer methods and authentication methods.
gil (git links tool) is a tool to manage complex recursive repository dependencies with cross references and cycles. This tool provides a solution to the git recursive submodules dependency problem. Written in Python.
git subrepo “clones” an external Git repo into a subdirectory of your repo. It is an alternative to git submodule and git subtree. The subrepo history is squashed into a single commit that contains the reference information. Recommended as replacement for the (no longer maintained) Git STree project.
tomono: Multi- to Monorepo Migration, is a script that merges multiple independent tiny repositories into a single “monorepo”. Every original repo is moved into its own subdirectory, branches with the same name are all merged.
- Can be considered the reverse of splitsh/lite tool, whose goal is to make splitting a monolithic repository to read-only standalone repositories easy and fast (mentioned in Git Rev News: Edition #16).
gitdm (the “git data miner”) is the tool that Greg KH and Jonathan Corbet have used to create statistics on where kernel patches come from. Written in Python. Original at git://git.lwn.net/gitdm.git
lolcommits: Git-based selfies for software developers. lolcommits takes a snapshot with your webcam every time you execute git commit, and archives a lolcat style image with it (image with embedded caption). Written in Ruby, requires a webcam and ImageMagick installed. See also Lolcommits from around the world! page on the project Wiki.
Steve’s Jujutsu Tutorial.
- Jujutsu (jj) is a version control system first mentioned in Git Rev News Edition #85; additionally, links to the LWN.net article and the Jujutsu: A Git-Compatible VCS talk about this version control system at Git Merge 2022 can be found in Git Rev News Edition #107.
Awesome Git is a curated list of amazingly awesome Git tools, resources and shiny things.
Awesome Git Hooks is a curated list of easy-to-use Git hooks for automating tasks during Git workflows.

Releases

Git 2.45.0, 2.45.0-rc1, 2.45.0-rc0
Git for Windows 2.45.0(1), 2.45.0-rc1(1), 2.45.0-rc0(1)
GitHub Enterprise 3.12.2, 3.11.8, 3.10.10, 3.9.13
GitLab 16.11.1, 16.10.4, 16.9.6, 16.11, 16.10.3, 16.9.5, 16.8.7, 16.10.2, 16.9.4, 16.8.6
Gerrit Code Review 3.8.5, 3.9.3, 3.9.4
GitHub Desktop 3.3.14, 3.3.13
tig 2.5.9
git-credential-oauth 0.11.2

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Junio Hamano, Štěpán Němec, Kristoffer Haugsbakk, Dragan Simic and Adam Johnson.

Git Rev News Edition 109 (March 31st, 2024)

chriscool — Sun, 31 Mar 2024 11:06:51 +0000

Git Rev News: Edition 109 (March 31st, 2024)

Welcome to the 109th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of February and March 2024.

Discussions

Reviews

[PATCH] rebase: make warning less passive aggressive

Harmen Stoppels sent a patch to the mailing list that changed an error message from “No rebase in progress?” to “No rebase in progress”. The rationale is that this error appears when one runs git rebase --continue while there is no rebase going on, so there is no reason for the question mark.

Junio Hamano, the Git maintainer, replied to Harmen suggesting using the imperative mood in the commit message, and saying that the change in itself is good but that the patch shouldn’t have touched the po/*.po files in the project that are used for localization. Junio also said that we could later add tests for this as it appeared there was none.

Michal Suchánek replied to Junio saying that it might have been OK to touch the po/*.po files if the patch had updated the translations in those files but it hadn’t.

Junio replied to Michal saying that knowing the target language was needed before removing question marks in those files as it might not be enough to change a question into a statement. Even if the author of the patch knew enough, reviewers of the patch might not, but the biggest problem was bypassing the languages teams.

Michal replied to Junio asking what was the problem “with not involving several language teams to remove a question mark”.

Jean-Noël Avila, who is a translator, replied that it didn’t bother him much to edit a sentence to remove a question mark and possibly adjust it, compared to “translating again and again similar sentences”.

This led to some confusion as Junio thought that Jean-Noël said that the “everything in one patch” approach would help translators by not having them translate “again and again”. But Jean-Noël clarified that he didn’t consider changing a question to an assertion is translating “again and again”. He agreed that it was perfectly fine for translators to have to do those kinds of changes. With “again and again” he was referring to strings like “could not stat ‘%s’” and then “could not stat file ‘%s’”.

In the meantime Patrick Steinhardt replied to Harmen’s initial message. He suggested converting the error message to start with a lowercase letter as our guidelines for error messages recommend.

Harmen then sent a version 2 of his patch which didn’t change any po/*.po file and had the error message start with a lowercase letter. Patrick reviewed that patch and found it good.

Kristoffer Haugsbakk chimed into the discussion saying he had interpreted the original error message as saying “I’m not quite sure but it looks like you are not in the middle of a rebase?”

Junio replied to Kristoffer saying that there are indeed examples of “less assertive” messages in the same rebase command, like “It looks like ‘git am’ is in progress. Cannot rebase.” But we should be more assertive as it could help us get valuable bug reports saying for example “The command said I was not rebasing, but I was! Here is what I did…” Such bug reports could help us improve how we determine the state we are in.

The version 2 of Harmen’s patch was later merged to the ‘master’ branch.

Developer Spotlight: Linus Arver

Who are you and what do you do?

I’m one of those so-called “self-taught” developers. My educational background is in English and tax law (I know, boring right?). Over a decade ago I thought I would be a corporate attorney, but in law school I discovered programming and fell completely in love with the craft, and never looked back! In hindsight it was the second-best decision I’ve made in life (the first being getting married to my lovely wife four years ago).

I said that I fell into programming during law school. But actually my original journey started in 7th grade when I tried to pick up C++. I remember learning control flow, structs and pointers in the first few chapters of the book I was using, but when it came to the chapter on OOP and classes, I could not understand why OOP was necessary. The book I was using just explained why OOP was great, and not why it would ever be bad.

Of course, years later I realized that OOP is one of several paradigms, so perhaps my instinct to question OOP as a panacea was onto something. In high school and university I remember tinkering with HTML and websites before smartphones became popular. What a simpler time it was, back then!

Fast forward to law school, where I had the idea of writing class notes using plaintext. Soon after I had the idea of converting these plaintext notes to prettified outlines, so I needed a way to convert them to HTML. For better or worse, all this happened before I discovered Emacs and Org mode (or even Markdown).

Anyway, I first wrote a plaintext-to-HTML converter in Ruby. Then I rewrote it in C just for fun. Then again in Haskell (using a minimal subset of Org mode syntax). As you can see, I sort of got carried away, haha.

I would go on to write dozens of pet projects (rudimentary chess engine, game modding tools, etc) where I got to write tons of code. I’ve had the “ugh, did I really write this?” moment too many times to count. I like to believe that I did the tech industry a favor by not entering it until I was well versed in fundamental programming and architectural concepts. 😉

Since those law school days I’ve taken an interest in learning more languages/ecosystems (e.g., Elixir and Rust). Recently, I’ve taken a renewed interest in Literate Programming. I’m toying with the idea of using it in a somewhat large scale in a future project. It takes a ton of work to do LP right, but in many ways it’s the best possible way to document code (case in point, the absolutely stellar documentation standards of the TeX community, such as the glorious TikZ user manual).

And I believe that readability is the most important attribute when it comes to code — even before correctness! Because at least if the intent of the author is clear, we can have a (fairly) easy way to fix things to make it correct. The other way around (correct, but unreadable code) suffers from stagnation because people become afraid of touching it, because it’s hard to understand. It becomes harder to extend and grow, which is required of any software worth maintaining (we call it software for a reason).

Going back to the question (sorry for rambling a bit there), in my $DAYJOB I work on microservices, APIs, and backend systems. Professionally I’ve always been a backend/infra engineer. In my spare time I contribute to this wonderful community!
What would you name your most important contribution to Git?

I would say my contributions to the documentation come out on top. At the end of the day, Git is meant for human consumption. So getting a bit more polish here and there for user-facing docs is well worth the trouble, and I am most proud of my work in this area so far.

If I had more time, I would overhaul the documentation to make things easier to understand. Truly, Git has a very simple conceptual model (thanks to the brilliance of its original author). You just have to understand that commits come from one or more other commits (sort of like family trees). That’s it! But sadly we have a reputation of having absolutely terrible user-facing docs, so much so that it pushed people away to Mercurial and other more friendly VCSs. We need to fix that.
What are you doing on the Git project these days, and why?

Last year I started trying to add unit tests to the (perhaps obscure) git interpret-trailers command, but this effort has morphed into “let’s also overhaul the entire subsystem around how trailers are handled, with the aim of creating a reusable C library around it” [ ref 1 ] [ ref 2 ].

I’m afraid I’ve bitten off more than I can chew, but I do have a backlog of about 60 patches that I need to get sent up for review. Not all at once, of course haha. Hopefully I can get these sent up and merged over the coming months. The review process can be lengthy you see, but for good reason — we take time to try to make sure things are right the first time.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

At the risk of being unoriginal, it would be libification (see Calvin Wan’s interview from edition 102). But to be more precise, it would be the complete banning of “shelling out” which we do in many places (where Git spawns another Git process to do something). Instead we could (and should) be using libraries internally inside Git’s own codebase. I believe that once we can get Git to start treating itself as a library, that external library consumption will soon follow.

There are many others interested in this area as Git has a massive footprint in our industry. I hope that the many large companies that benefit from Git can grow their roster of Git contributors.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

git checkout. I believe git switch and git restore replaced the need to have git checkout. I believe in the “there should be only one way to do the right thing” camp when it comes to the CLI, so I don’t like how we have multiple commands with a lot of overlap.

I say this even though personally I’ve been using Git for over 15 years and have always used git checkout (even after the introduction of git {switch,restore}). Simplicity matters!
What is your favorite Git-related tool/library, outside of Git itself?

Tig. I use it all the time, every day. It’s so good that I basically never use git log, unless I’m searching through it interactively with the pager.

Every time I see someone proudly showing off their latest “git-log” incantation (with all its bells and whistles), I think to myself “I guess they’ve never heard of tig”.

Being an Emacs user, I tried to get into Magit but could not get used to the keybindings that conflicted with my Vim-styled bindings. (Yes, I use Evil mode via Doom Emacs if you’re into that sort of thing.) OTOH I get so much done with the basic git-* commands and tig that I’m rather happy with my workflow.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Nine years ago, I contributed my first patch series. I was so proud of this work that I wrote a blog post about it.

The TL;DR of that post is that anyone can contribute to Git, and really we are a welcoming community. Junio goes out of his way to accommodate new contributors (I admire his patience), so please, feel free to join us!
What is your toolbox for interacting with the mailing list and for development of Git?

So my first contribution 9 years ago was via (the traditional) git send-email command. These days there is this very neat service called GitGitGadget that allows you to create pull requests on GitHub and does all the housekeeping work of keeping mailing list discussions in sync (you’ll get comments on your PR which come from mailing list responses). Plus you can get previews of your patch series (exactly how they’ll look like on the list) before you submit it, which is always nice.

For local Git development, honestly I don’t do anything special or unusual. One window for Emacs, one window for (re)compiling Git and running tests, and maybe one more for Tig. From Emacs I use notmuch to browse the mailing list emails (which I sync to Gmail with lieer).

I use Org mode in Emacs heavily for organizing code snippets and ideas.

Last but not least, I use tmux to organize terminal windows and navigate quickly across them, even if I’m not using SSH.
What is your advice for people who want to start Git development? Where and how should they start?

The hard part is figuring out which area you want to work on. Git has a large codebase, so I recommend starting out with documentation changes to familiarize yourself with the current state of things. There’s always a typo or grammofix hiding in there!

Many of our manpages read like dictionaries, when they should read more like user guides. Some manpages have helpful “EXAMPLES” sections to show you how to actually use various options and commands, so if you can think of additional examples, that would be most welcome. Getting familiar with how things work with user-facing docs should help you understand the intent behind the large C codebase we have.

Try to make your contributions as small as possible, but make an effort to write good commit messages. Copy the style of veterans like Junio, Peff (Jeff King), Christian Couder, and others I am forgetting (sorry!) who’ve been doing this for a long time.

Once your change is submitted, nag people weekly to get things moving (yes, we need prodding occasionally). But also don’t get offended if there are a lot of review comments for seemingly small things — we’re just trying to maintain a certain level of quality. Git is used by almost everyone in the software industry, so it’s important for us to keep a high bar for quality, that’s all.
If there’s one tip you would like to share with other Git developers, what would it be?

Junio has been our maintainer for nearly two decades. It’s a tough job and somehow he’s kept going at it all this time. Still, let’s do our best to help make his job easier, because honestly we are truly lucky to have someone of his caliber lead our project.

More concretely, this means helping out with code reviews. If you’re not sure which ones to review, see the “What’s Cooking” emails that Junio sends out regularly to look for patches that need help from reviewers. They are commented as “Needs review” or “Comments?”, so they’re easy enough to spot.

Cheers!

Other News

Light reading

Julia Evans continues her series of blog posts about Git with How HEAD works in git and The “current branch” in git. The first entry in this series of blog posts can be found in Git Rev News Edition #103.
Keeping repository maintainer information accurate: ensuring that the CODEOWNERS file is up to date with the help of tools like cleanowners. By Zack Koppert on GitHub Blog.
De Programmatica Ipsum, Issue #66: Version Control - Twenty Years Is Nothing by Adrian Kosmaczewski.
Git Worktrees and GitButler: How do Git worktrees help you work on more than one branch at the same time, and how does that differ from virtual branches in GitButler? Written by Scott Chacon on GitButler Blog.
Fixing up [a series of] Git [commits] with Autosquash by Scott Chacon on GitButler Blog.
Advanced git commands every senior software developer needs to know by Otto Kekäläinen on Optimized by Otto blog.
Five Ways to Be More Productive with Git by Paul Redmond on Laravel News blog. The blog post lists a few useful Git aliases, setting up a commit template, using password manager for SSH keys (that can be used for signing commits), making use of the GitHub CLI tool (gh), and configuring mergetool and difftool.
Git: programmatic staging (with the help of the expect tool, or with grepdiff) by Ilia Choly on Choly’s Blog. The author uses described technique as a cleanup step after rewriting/refactoring code using automatic tools, such as Semgrep, ast-grep, LLMs (Large Language Models) such as ChatGPT, and one-off scripts.
- Semgrep was mentioned in Git Rev News Edition #75; you can test it with Semgrep Playground.
- Another article by the same author mentions other similar tools, namely CodeQL (mentioned in passing in Git Rev News Edition #79), and Comby. It also talks about the newly created semgrepx tool for rewriting semgrep matches using externals tools (such as Datasette’s llm CLI tool and Python library).
Unleashing the Power of Git Bisect by Shai Almog on DZone (DevOps Zone).
Moving Code from One Repository to Another Using Git Patch by Joel Colaco on his blog - though a better solution would be to use git format-patch and git am (or alternates and git cherry-pick).
Extremely Linear Git History, with first commit in a repo having a hash that starts with 0000000, the second commit is 0000001, and so on; written by Gustav Westling on his blog (2022).
Witty.rb - A very simple Ruby Script demonstrating how to parse a Git index file (.git/index). Published as Gist by Chubak Bidpaa.
Dr. Git-Love or: How I Learned to Stop Worrying and Love the Rebase are HTML slides for Git training course by Pablo Vergés (escodebar).
Toy/demo: using ChatGPT to summarize lengthy LKML threads (b4 integration) thread on Linux kernel mailing list, started by Konstantin Ryabitsev.

Easy watching

So You Think You Know Git Part 2 - DevWorld 2024 by Scott Chacon on GitButler YouTube channel, continues the FOSDEM version of the talk, which was mentioned in the previous Git Rev News. DevWorld Git Slides are available on GitButler Blog.

Git tools and sites

extremely-linear, also known as git-linearize, is a tool to create commits with SHA-1 identifier beginning with 0000000 for the first commit, 0000001 for the second, 0000002 for the third, and so on. This tool uses lucky_commit, which inserts invisible whitespace characters at the end of the commit message until it gets a SHA-1 (or SHA-256) hash with the desired prefix.
- Compare and contrast with git-vain (mentioned in Git Rev News Edition #103) and git-vanity-sha (mentioned in Git Rev News Edition #39), tools to generate vanity hashes (for example to make the SHA-1 hash of HEAD begin with c0ffee).
Nosey Parker is a command-line program that finds secrets and sensitive information in textual data and Git history. Written in Rust, under Apache 2.0 license.
gitu - a TUI Git client inspired by Magit. Written in Rust, under MIT license.
Vim-Flog is a powerful Git branch viewer for Vim. Requires Neovim or Vim with Lua support.
gcd - Git worktree navigator, lets you quickly navigate to Git worktrees on your filesystem, and to directories within your current worktree. Written as a set of shell functions to be sourced into ~/.zshrc or ~/.bashrc.
grepdiff is a command-line tool that reads unified diffs from the files passed as arguments (or standard input), and prints a reduced diff containing only the hunks matching a regular expression. Written in Go.
Gitstr is a tool to send and receive Git patches over Nostr, using NIP-34.
- Compare and contrast with git-ssb (see git-ssb-intro guide): decentralized Git repo hosting and issue tracking on Secure-ScuttleButt (SSB), mentioned in Git Rev News Edition #26 and #40.

Releases

libgit2 1.8.0
Gerrit Code Review 3.7.8, 3.9.2
GitHub Enterprise 3.12.1, 3.11.7, 3.10.9, 3.9.12, 3.8.17, 3.12.0, 3.11.6, 3.10.8, 3.9.11, 3.8.16
GitLab 16.10.1, 16.9.3, 16.8.5, 16.10, 16.9.2
GitKraken 9.13.0
GitHub Desktop 3.3.12, 3.3.11, 3.3.10
Tower for Windows 6.0 (Release blog post)
Tower for Mac 10.5
git-credential-azure 0.3.0

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Linus Arver, Eric Sunshine, Ghanshyam Thakkar, Kristoffer Haugsbakk, Štěpán Němec, Junio Hamano and Bruno Brito.

Git Rev News Edition 108 (February 29th, 2024)

chriscool — Thu, 29 Feb 2024 11:06:51 +0000

Git Rev News: Edition 108 (February 29th, 2024)

Welcome to the 108th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of January and February 2024.

Discussions

Support

[Bug?] “git diff --no-rename A B”

Junio Hamano, the Git maintainer, sent an email to the mailing list saying that when git diff was used with --no-rename instead of --no-renames, rename detection was still performed. He wondered if that was a bug, because either --no-rename should be interpreted as being a shortened form of --no-renames, which is a valid option and should disable rename detection, or --no-rename should be rejected with an error message and termination of git diff.

Dragan Simic replied to Junio that indeed, in case the option is not recognized, an error message should be emitted.

Jeff King, alias Peff, also replied to Junio saying he tried --no-foo, which properly errored out. He then wondered if it could be a bug in the parse-options code that could be confused because git diff has both --[no-]rename-empty and --no-renames. As there is an abbreviation ambiguity between --no-rename-empty and --no-renames when --no-rename is used, the parse-options code should not allow such an abbreviation and should error out.

He suggested, as an alternative to fixing the bug, that a new --renames option could be introduced. It would be synonymous to --find-renames, which is currently the only opposite to --no-renames. He proposed a patch to do that and showed that after his patch, --no-rename would properly error out.

René Scharfe replied to Peff that the issue came from a patch written in 2019 that disabled abbreviated options when there could be an ambiguity. The code handling abbreviations would trigger not only if the condition guarding it was satisfied, but also if it was reached through a goto statement. The patch disabling abbreviated options only took care of the condition guarding that code, but not of the goto statement. Along with these explanations, René provided a patch fixing the bug.

Junio thanked René for spotting the “nasty” bug and said he agreed that the code was confusing.

René replied to Junio with a follow-up patch removing the goto statement.

Peff also replied to René’s first patch wondering if it fixed all the possible issues, but then in a reply to himself agreed that René’s patch was indeed fixing all the issues discussed.

Junio later merged both of René’s patches, and they were part of the recently released Git versions 2.43.2, 2.43.3 and 2.44.0.

Bonus reading: “A Case against the GO TO Statement” by Edsger W. Dijkstra

Other News

Various

The Git project has been accepted as a Mentor Organization for Google Summer of Code (GSoC) 2024. We can still add project ideas to our idea page, and volunteers to (co-)mentor are still welcome. Feel free to join the discussion in the corresponding thread. Also, feel free to spread the word about Git’s participation.
Highlights from Git 2.44 by Taylor Blau on GitHub Blog.
GitLab’s contributions to Git 2.44.0 by Patrick Steinhardt on GitLab Blog.

Light reading

Git Tips and Tricks: a 3 part series by Scott Chacon on GitButler blog, accompanying the video from the talk So You Think You Know Git - FOSDEM 2024 (available on YouTube); find the talk slides (and later the “official” video) in the FOSDEM archive.
- Git Tips 1: Oldies but Goodies: conditional configs, git blame and log with line ranges (-L), git blame with following, word diff, resolution reuse (git rerere).
- Git Tips 2: Some Subtle New Things: git branch stuff (--sort, --column), safe force-pushing (--force-with-lease), SSH commit signing, push signing, git maintenance.
- Git Tips 3: Really Large Repositories and Monorepos: prefetching, commit graph, filesystem monitor, partial cloning, sparse checkouts, the scalar tool.
Git Trailers by Brooke Kuhlmann. Learn how to leverage commit metadata for powerful automations and more human-readable commit messages.
More Expressive Commits with Gitmoji ☺️ by Bruno Brito on Tower’s blog.
- Gitmoji was first mentioned in Git Rev News Edition #47, though then under a different URL (which now redirects to the current one).
- The similar Emoji-Log commit log messages standard was mentioned in Git Rev News Edition #101.
My Git pre-commit hook contained a footgun by Mark Dominus (陶敏修) on his blog (The Universe of Discourse).
Julia Evans continues her series of blog posts about Git with Dealing with diverged git branches and Popular git config options. First entry in this series can be found in Git Rev News Edition #103.
Git Battle: YOLO Mode vs. Clean History by Hana Klingová on her blog (and also on DEV.to): about usefulness of git commit --fixup and rebase.autosquash.
Restore deleted/lost files with git by Leonardo Montini for This is Learning, part 6 of git better - Improve your git skills (6 Part Series). Originally published at leonardomontini.dev (includes video version).
My favourite Git commit (2019) by David Thompson on his blog, about the benefits of good commit messages (the example is a one-character change).
Includes links to the following recommended articles on the same topic:
- Telling stories through your commits by Joel Chippindale (2016).
- A branch in time by Tekin Süleyman (2019).
Contribution experience report: Git by Antonin Delpeuch on his blog.

Easy watching

So You Think You Know Git - FOSDEM 2024 by Scott Chacon on YouTube, 47 minutes long (mentioned above).

Git tools and sites

Milestoner by Brooke Kuhlmann. Significant updates have been made where you can build release notes from your commit messages based on Git notes and trailers in multiple formats: console, AsciiDoc, Markdown, and HTML. Includes automatic calculation of your next version and automatic tagging.
git-cliff is a highly customizable changelog generator using regex-powered custom parsers that can generate changelog files for any Git repository which follows the conventional commits specification. Written in Rust as a command-line application.
LearnGit.io is an upcoming resource for learning Git using videos with motion graphics. The project is by Jack Lot who posts Git videos on The Modern Coder YouTube channel. Jack is looking for intermediate/advanced Git users for feedback. If interested email <jack@learngit.io>.
pg-diff is a PostgreSQL schema and data comparing tool. Written in JavaScript by Michael Sogos.
Another trivial utility: git-q by Mark Dominus available from mjdominus personal git-util repository as git-q.
Aho is a Git implementation in AWK. It is a toy project to explore some of the internals of Git and newer features of GNU AWK (aka Gawk).

Releases

Git 2.44.0, 2.43.3, 2.44.0-rc2, 2.43.2, 2.44.0-rc1, 2.44.0-rc0, 2.43.1
Git for Windows 2.44.0(1), 2.44.0-rc2(1), 2.44.0-rc1(1), 2.44.0-rc0(1)
GitLab 16.9.1, 16.8.3, 16.7.6, 16.9, 16.8.2, 16.7.5, 16.6.7
Gerrit Code Review 3.7.7, 3.8.4
GitHub Enterprise 3.12.0, 3.11.5, 3.10.7, 3.9.10, 3.8.15, 3.11.4, 3.10.6, 3.9.9, 3.8.14
GitKraken 9.12.0
GitHub Desktop 3.3.9
Sourcetree 4.2.7
Tower for Mac 10.4
git-credential-oauth 0.11.1

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Brooke Kuhlmann, Jack Lot, Štěpán Němec and Bruno Brito.

Git Rev News Edition 107 (January 31st, 2024)

chriscool — Wed, 31 Jan 2024 11:06:51 +0000

Git Rev News: Edition 107 (January 31st, 2024)

Welcome to the 107th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of December 2023 and January 2024.

Discussions

Support

Git Rename Detection Bug

Jeremy Pridmore reported an issue to the Git mailing list. He used git bugreport, so his message looks like a filled out form with questions and answers.

He was trying to cherry-pick changes from one repo (A) to another (B), while both A and B came from the same original TFS server but with different set of changes. He was disappointed though because some files that had been moved in repo A were matched up by the rename detection mechanism to files other than what he expected in repo B, and he wondered if the reason for this was the new ‘ort’ merge strategy described in a blog post by Elijah Newren.

While not obvious at first, Jeremy’s primary problem specifically centered around cases where there were multiple files with 100% identical content. For example, originally there could have been an orig/foo.txt file, while one of the descendant repos does not have that file anymore but instead has two files, dir2/foo.txt and dir3/foo.txt, both with contents identical to the original orig/foo.txt. So, Git has to figure out which one of dir2/foo.txt and dir3/foo.txt is the result of renaming orig/foo.txt.

Elijah replied to Jeremy explaining extensively how rename detection works in Git. Elijah pointed out that Jeremy’s problem, as described, did not involve directory rename detection (despite looking kind of like a directory rename detection problem). Also, since Jeremy pointed out that the contents of the “misdetected” renames had identical contents to what they were paired with, that meant that only exact renames were involved. Because of these two factors, Elijah said that the new ‘ort’ merge strategy, which he implemented, and which replaced the old ‘recursive’ strategy, should use the same rename detection rules as that old strategy for Jeremy’s problem. Elijah suggested adding the -s recursive option to the cherry-pick command to verify this and check if it worked differently using the old ‘recursive’ strategy.

Elijah also pointed out that for exact renames in a setup like this, other than Git giving a preference to files with the same basename, if there are multiple choices with identical content then it will just pick one essentially at random.

Jeremy replied to Elijah saying that this sounded like what he was observing. He gave some more examples, showing that when there are multiple 100% matches, Git didn’t always match up the files that he wanted but matched files differently. Jeremy suggested that filename similarity (beyond just basename matching) be added as a secondary criteria to content similarity for rename detection, since it would help in his case.

Elijah replied that he had tried a few filename similarity ideas, and added a “same basename” criteria for inexact renames in the ort merge strategy along these lines. However, he said other filename similarity measurements he tried didn’t work out so well. He mentioned that they risk being repository-specific (in a way where they help with merges in some repositories but actually hurt in others). He also mentioned a rather counter-intuitive result that filename comparisons could rival the cost of content comparisons, which means such measurements could adversely affect performance and possibly even throw a monkey wrench in multiple of the existing performance optimizations in the current merge algorithm.

The thread also involved additional explanations about various facts involving rename detection. This included details about how renames are just a hint for developers as they are not recorded, but are instead computed from scratch in response to user commands. It also included details about what things like “added by both” means (namely that both sides added the same filename but with different contents), why you never see “deleted by both” as a conflict status (there is no conflict; the file can just be deleted), and other minor points.

Elijah also brought up a slightly more common case that mirrors the problems Jeremy saw, where users could be surprised by the per-file content similarity matching that Git does. This more general case arises from having multiple copies of a versioned library. For example, you may have a “base” version with a directory named “library-x-1.7/”, and a “stable” version has many changes in that directory, while a “development” branch has removed that directory but has added both a “library-x-1.8/” and a “library-x-1.9/” directory which both have changes compared to “library-x-1.7/”. In such a case, if you are trying to cherry-pick a commit involving several files modified under “library-x-1.7/”, where do the changes get applied? Some users might expect the changes in that commit to get applied to “library-x-1.8/”, while others might expect them to get applied to “library-x-1.9/”. In practice, though, it would not be uncommon for Git to apply the changes from some of the files in the commit to “library-x-1.8/” and changes from other files in the commit to “library-x-1.9/”. Elijah explained why this happens and suggested a hack for users dealing with this particular kind of case to work around rename detection.

Philip Oakley then chimed into the discussion to suggest using “BLOBSAME” for exact renames in the same way as “TREESAME” is used in git log for history simplification. Elijah replied to Philip that he thinks that ‘exact rename’ already works. Junio C Hamano, the Git maintainer, then pointed out that “TREESAME” is a property of commits, not trees, and suggested using words other than “BLOBSAME” and “TREESAME” in the context of rename detection.

Philip and Elijah discussed terminology at more length, agreeing that good terminology can sometimes help people coming from an “old centralised VCS” make the mind shift to understand Git’s model, but didn’t find anything that would help in this case.

Finally, Philip requested more information about how Git computes file content similarity (for inexact rename detection), referencing Elijah’s mention of “spanhash representation”. Elijah explained the internal data structure in detail, and supported his earlier claim that “comparison of filenames can rival the cost of file content similarity computations”.

Other News

Various

The contributions GitLab’s Git team made to the Git 2.43 release by John Cai on GitLab Blog.
- See also Highlights from Git 2.43 by Taylor Blau on GitHub Blog, covering different changes, included in Git Rev News Edition #105.
GitHub has Copilot, GitLab has Duo Code Suggestions; now Bitbucket has integration with Tabnine: Accelerate your development process with Tabnine AI and Bitbucket.

Light reading

I Taught GIT to High School Students: My Experience as Linux Day Mentor by Coluzzi Andrea on his blog (and also on DEV.to).
How Framer Manages Their Codebase with Tower by Bruno Brito on Tower’s blog.
Julia Evans continues her series of articles about Git with Do we think of git commits as diffs, snapshots, and/or histories? and Inside .git (the latter in both a comic and a text version).
Minimal contents of a .git folder by Manuel Strehl on A Peculiar Zoo of Thoughts blog.
Git Config Settings I Always Recommend by Brandon Pugh on DEV.to (and also on his blog); though setting pull.rebase to true depends on whether project prefers merges or rebases, and is very project-dependent.
Git Lesson: How to Use .gitignore and .gitkeep? by Rita {FlyNerd} Lyczywek on DEV.to (translated from original article in Polish).
Git Prom! My Favorite Git Alias (to fetch the latest upstream HEAD and rebase your current branch on top of it) by Matt Butcher on DEV.to.
Integrating DVC and Git LFS via libgit2 filters by Peter Rowlands on DVC AI Blog. DVC (Data Version Control) was first mentioned in Git Rev News Edition #42, with links to different articles about it in #42, #63, #64, #72, and #100.
Version Control for Machine Learning by Nikitha Narendra on DagsHub Blog. The DAGsHub service was first mentioned in Git Rev News Edition #72; further articles about this web platform for data version control linked in Edition #85, #96, and #97.
RFC: Bridging GitHub workflows with b4 by Konstantin Ryabitsev on Linux kernel tools mailing list via lore.kernel.org.
Jujutsu: a new, Git-compatible version control system by Daroc Alden on LWN.net (free link). Jujutsu was first mentioned in Git Rev News Edition #85; there was also a Jujutsu: A Git-Compatible VCS talk by Martin von Zweigbergk at Git Merge 2022, mentioned in passing in Git Rev News Edition #91.
Praise, Criticism, and Dialogue (in open source code review process) by Robert Haas (PostgreSQL contributor) on his Blogspot blog.
Being friendly: friendly forks 101 and Being friendly: Strategies for friendly fork management by Lessley Dennington on GitHub Blog (2022).

Git tools and sites

Git-RDM had intended to be a Research Data Management (RDM) plugin for the Git version control system. It interfaces Git with data hosting services to manage the curation of version controlled files using persistent, citable repositories. Access to hosting services is managed with PyRDM library, which supports Figshare, Zenodo, and (in a limited fashion) DSpace-based services using SWORD protocol version 2. Written in Python, last released in 2016.
- See also the “Git-RDM: A research data management plugin for the Git version control system” article in The Journal of Open Source Software (2016).
GitVision is a web tool designed to visualize Git repositories in virtual, augmented, and 3D reality. Developed with Vue 3 in Vite by Kacper Konecki (GaspardIV). There is a live demo of GitVision at gitvis.web.app, including quite a few tiny, small, medium and large example repositories; you can also visualize your own repository by uploading data prepared using GitVision script (or you can use the tool locally).
- It provides a type of 3D visualization different from the much better known Gource visualization tool for source control repositories. There the repository is displayed as a tree where the root of the repository is the center, directories are branches and files are leaves. Contributors to the source code appear and disappear as they contribute to specific files and directories.
- Has different purpose than Git History.xyz web app that allows to quickly browse the history of files in any git repo, mentioned in Git Rev News Edition #48 and #105.
- See also the VR-Git: Git Repository Visualization and Immersion in Virtual Reality (PDF) paper by Roy Oberhauser (2022).
The Visualize Git web app illustrates what’s going on under the hood when you use common Git operations. You’ll see what exactly is happening to your commit graph. Powered by D3. Sources on GitHub as git-school/visualizing-git. This app is quite similar to the free playground mode of Visualizing Git Concepts with D3, first mentioned in Git Rev News #69. Compare with:
- Learn Git Branching, mentioned first in Git Rev News Edition #30.
- Git Gud, a visual web-based Git simulator, meant to help understand Git better, announced by its author Nic Hartley in Git Gud at git. First mentioned in Git Rev News Edition #48.
- Git Gud, a command line game designed to help you learn how to use the Git version control system. Written in Python by Ben Thayer. First mentioned in Git Rev News Edition #72.
- Oh My Git!, an open source game about learning Git, written using the Godot game engine (source). There was a lightning talk about this game at FOSDEM 2021: Building a Git learning game: A playful approach to version control. First mentioned in Git Rev News Edition #72.
- Git-Sim tool (written in Python) to visually simulate Git operations in your own repos with a single terminal command. Described in Git-Sim: Visually Simulate Git Operations In Your Own Repos (mentioned in Git Rev News Edition #95) and Git-Sim 3 Month Dev Update: Community Response, New Features, & The Future (mentioned in Edition #98).
List of git mistakes people have listed on Mastodon, gathered by Julia Evans (@b0rk@jvns.ca).

Releases

GitHub Enterprise 3.11.3, 3.10.5, 3.9.8, 3.8.13
GitLab 16.8.1, 16.7.4, 16.6.6, 16.5.8, 16.8, 16.7.3, 16.7.2, 16.6.4, 16.5.6
Bitbucket Server 8.17
GitKraken 9.11.1
GitHub Desktop 3.3.8, 3.3.7
Tower for Mac 10.3
Tower for Windows 5.5

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Elijah Newren, Bruno Brito, Brandon Pugh and Štěpán Němec.

Git Rev News Edition 106 (December 31th, 2023)

chriscool — Sun, 31 Dec 2023 11:06:51 +0000

Git Rev News: Edition 106 (December 31th, 2023)

Welcome to the 106th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of November and December 2023.

Discussions

Reviews

[PATCH 0/4] Switch links to https

In September, Josh Soref posted a 4-patch series on the mailing list to improve the URLs used throughout the documentation and the code base of the project.

The main goal was to use HTTPS instead of HTTP in the URLs to improve user security, but along the way some patches replaced URLs that didn’t work anymore with some new ones pointing to the same content.

Eric Sunshine replied to Josh’s patches asking why one URL was changed from http://json.org/ to https://www.json.org/ instead of just replacing http with https. Josh replied that it was because that website was self-identifying with the latter URL using a meta refresh.

In the meantime, Junio Hamano, the Git maintainer, replied to some patches saying that it might not be worth updating some URLs, either because it was clear from the context that they were old, or because they were part of some code we borrowed from other projects. In some cases, they were an argument of a Git command and still just worked, while the meaning of the command changed a bit when http was replaced with https. Junio liked the fact that some broken links were fixed by the series though.

Josh then sent a version 2 of his patch series. This took into account Eric’s comments as a commit message was improved to say that some changes were made to respect a site’s self-identification. Junio’s comments were also taken into account as a number of URLs that were previously changed were now left as-is.

Elijah Newren and Junio commented on this new version. They both suggested improving commit messages or the cover letter of the series to better explain the reasons for the changes that were made. In one case, Elijah and Josh discussed replacing the URL of a website that seemed to be often down with a link to its content on the Internet Archive.

In November, Josh then sent a version 3 of his patch series where the first and second patches had been swapped to avoid some confusion for reviewers who would ask why some URLs weren’t changed in the first patch overlooking that the second one would change them.

The other significant change compared to version 2 was that Josh decided not to replace the URL of the website that was often down saying “we’ll risk users getting hacked content from an arbitrary MITM instead of taking archived authenticated content based on the last time their web site was properly maintained”.

Elijah replied that he would be fine with using the archived link if it was better justified in the commit message, but said that he also agreed with merging the whole series as-is, as he had checked all the links and they all looked good to him.

Josh replied he could come back later to change the URL and preferred the series to be merged as-is. He thanked Elijah for taking the time to re-check every link, saying he knew exactly how tedious that is.

Junio agreed with merging the series, which is now part of the ‘master’ branch.

Community Spotlight: VonC

VonC is a prolific contributor to the Git topic on Stack Overflow. This edition features an interview with him. Thanks to our survey respondents for suggesting to interview VonC!

Who are you and what do you do?

By day, I am an information technology consultant working for a computer services company in France. By night, I am VonC on Stack Overflow, and I have contributed to various topics since its early days (Sept. 2008). I do that every single day. It includes answering questions about Git: almost 16K answers in 15 years.
What would you name your most important contribution to Git?

I do not contribute to Git directly, but I report on Stack Overflow any interesting git/git commits which provides a new answer to old questions.

I started in 2012 with questions like “Squash the first two commits in Git?” and “How do I remove a submodule?”. Then 1630 commits followed over the next decade.
Why answering questions about Git on Stack Overflow?

As I mentioned in “How to earn a million reputation on Stack Overflow: be of service to others”, by Ryan Donovan, this is a way to give back to the community, and to learn in the process.

I learnt Git itself even before installing it, by answering a few questions on Stack Overflow, as I detailed in “How’d you get started?”.
If you could get a team of expert developers to work full-time on something in Git for a full year, what would it be?

I mentioned in 2013/2016 the issue of storing large files in Git repositories.

But nowadays, I would work on the workflow side of Git, and how to make it easier to use for beginners. I follow GitButler and Scott Chacon’s work.

GitButler is rethinking everything between when you write code in your editor of choice and when you push that code to GitHub for review. Why are you making ‘wip’ commits when your SCM should be recording everything for you? Why are everyone’s commit messages close to useless? Why is git blame the best way to get context on the code your team has written? Why can’t you seamlessly transition work between computers?
If you could remove something from Git without worrying about backward compatibility, what would it be?

git checkout! It is time. As I explained in 2020, the git switch/git restore commands are “experimental” in name only, and are here to stay.
What is one of your most favorite features of Git?

Coming from CVS/SVN, one of my favorite features of Git is its powerful branching and merging capabilities. Branches in Git are lightweight and switching between them is fast, making it convenient to manage multiple streams of work simultaneously (and you have git worktree if you want to preserve your current working tree).

I use those branches and merges with “gitworkflow” (one word), using long-lived integration branches (like “master/main/release”), and “ephemeral” integration branches (like “public/next/devel”, created for a specific release cycle, then deleted and recreated for the next release cycle). See more at “gitworkflow workflow” and “Handle Git branching for test and production”.
What is your favorite Git-related tool/library, outside of Git itself?

I often used github.com/github/gitignore (“A collection of .gitignore templates”). I have also used and promoted git filter-repo, to remove large files from a Git repository.
Could you brief a bit about one of your most memorable experiences with Git?

My first git clone.

As mentioned in “How to earn a million reputation on Stack Overflow: be of service to others”, at the time I stumbled upon Git (2008/2009), I was managing big Rational ClearCase repositories of terabytes of data. The idea of cloning a full (Git) repository on my laptop was… incongruous, to say the least!

I am aware of the debate around monorepo vs. multirepo (which sometimes goes in hand with the debate around monolith vs. microservices), but I found in the subsequent years that working with multiple small Git repositories was much more manageable than working with a single large one, as I used to do before, using huge ClearCase VOBs.
What is your advice for people who want to start using Git? Where and how should they start?

Start with understanding Git branching, and operations around branches (switch, merge, rebase, cherry-pick).

For that, I always redirect people to “Learn Git Branching” (learngitbranching.js.org): nothing to install, all exercises are done directly in the browser, and it is very visual.

I also discourage people from blindly following the “Git Branching Model”, where an integration branch like develop is merged to another integration one like master. See the links above for “gitworkflow” where I explain why one should merge to an integration branch, not from it: merging from it means you are merging everything currently integrated into that branch. If you want to “exclude” some of those integrated commits, that becomes a nightmare to manage.
There’s a common conception that “Git is confusing”. What are your thoughts about the same?

Right… you mean XKCD 1597, Oct. 2015, “Git”.

The level of integration of Git in IDEs (like Eclipse, IntelliJ, VSCode, …) has made Git more accessible to beginners. I often redirect them to a combo VSCode + GitLens, and that is enough to get them started.

As long as the workflow is clearly defined, and the rebase is understood, for managing pull request (you rebase your local feature branch on top of the target branch, before force pushing it to the remote repository, with lease or if-includes), the users manage to get by. The bulk of my training is about the PR (Pull Request) workflow, which involves git rebase (--onto), and git push --force-with-lease or --force-if-includes.

But clarifying why Git exists, and where it comes from (I have younglings who have no idea who Linux Torvalds is, and his role in the creation of Git) can help. Git comes with a certain vision of how a VCS should work, and it has a lot to do with the way the Linux kernel is developed.
If there’s one tip you would like to share with other users of Git, what would it be?

Stop using git checkout, start using git switch/git restore instead!

Editor’s note: We hope you enjoyed this interview. We’ll explore if we could interview other such contributors who don’t directly participate in the mailing list. If you have any suggestions, you’re most welcome to share them with us through our issue tracker or by writing an email to <kaartic.sivaraam@gmail.com>.

Other News

Various

Google Summer of Code 2024: Contribute to GitLab and Git to prepare by Christian Couder and Nick Veenhof on GitLab Blog.
Upcoming changes to repository insights [on GitHub] on GitHub Blog.
Git platform AllSpice now curries favor with enterprises by Christine Hall on TechCrunch.
GitLab Duo Code Suggestions is generally available by David DeSanto on GitLab Blog. GitLab Code Suggestions is an alternative to GitHub Copilot and (to a lesser extent) OpenAI ChatGPT.

Light reading

Julia Evans continues her streak of Git-related blog posts with Mounting git commits as folders with NFS (and FUSE), about the experimental git-commit-folders tool. This tool was mentioned in previous Git Rev News.
Julia Evans also published a few comics about Git at Wizard Zines comics, for a zine on Git that she is currently writing (these are only the most recent ones; some earlier comics made it into Oh Shit, Git! Recipes for getting out of git mess zine):
- every git jargon
- git discussion bingo
- every git command I use
- meet the branch
- branches have no rules (at least no built-in ones, though you can try to enforce some with git hooks)
- HEAD and heads
- my rules for rebasing
Every engineer should understand git reflog by Harsh Siriah on Graphite Blog.
Fine-grained file differences by John D. Cook on his blog.
DiffDebugging by Martin Fowler on his blog/wiki. Page created in 2004, rewritten in 2013.
Monorepo, Poly-repo, or No Repo at all? Using Bit to make “irreversible decisions” easy to make and change. by Eden Ella on Bits and Pieces blog.
- Bit, a build system for composable software, was first mentioned in Git Rev News Edition #45 (then at the old bitsrc.io URL).
- It was mentioned again in Git Rev News Edition #77 in How to Collaborate on Components across Projects with Bit by Eden Ella on DEV.to.
Recovering Deleted Files From Your Git Working Tree by Oluwasanmi Akande on Smashing Magazine.
Git Grep Like a Pro: The Complete Guide by Bruce Johnston on Kosli Blog (2022).
Flexible Identities in git proposal (to avoid “deadnaming” and bury an old name while preserving a link to things done under the old name) by Jordan Rose on -dealloc blog (2020).

Easy watching

Git From the Bits Up by Tim Berglund, DataStax. Recorded at Jfokus 2016.

Git tools and sites

dyff /ˈdʏf/ is a diff tool for YAML files, and sometimes JSON. Can be used as Git diff driver (see documentation). Written in Go, uses MIT license.
Git-LaTeXdiff is a tool to graphically visualize differences between different versions of a LaTeX file. It is a wrapper around Git and latexdiff (which is present on CTAN, Comprehensive TeX Archive Network). git-latexdiff is written as a BSD-licensed Bash script, while latexdiff is written in Perl (and is GPLv3-licensed). The git-latexdiff tool was mentioned in passing in Git Rev News Edition #8.
git-oops is a very experimental tool allowing to undo a Git operation without having to remember the specific invocation, in the style of the undo features in GitUp, jj, and git-branchless. According to its author, it is meant as just a prototype serving “as inspiration for a better tool that actually works reliably” (see the repository README for details). Written in Python, MIT license. Prior art includes:
- One of git-oops inspirations, the undo command in git-branchless, described in git undo: We can do better, which was mentioned in Git Rev News Edition #76.
- A very basic and limited Git Undo [alias], mentioned in Git Rev News Edition #19 (resets state using reflog).
- Many IDE and programming editors, their Git-related extensions/plugins, and Git GUIs have some kind of universal “git undo”. One example is Tower Git GUI, whose undo abilities are described in CMD+Z for Git is Here (mentioned in Git Rev News Edition #65). Contrast with tools of similar scope and/or name, but which do something different:
- thefuck, a command line application which corrects your previous console command (for example Git command) if you made an error and it didn’t do what you wanted; the tool was mentioned in Git Rev News Edition #101.
- git-undo-el, a command for Emacs editor to “undo” changes to selected region of a file through its Git history, mentioned in Git Rev News Edition #34.
git-vee is a shell script that prepares a brief summary of how your current branch has diverged from a corresponding remote branch. Mentioned on git-vee slide in Cleaner git history (also known as “Stop merging master”) by Mark Jason Dominus (the author of the tool), from 2013.
Breezy is a version control system implemented in Python with multi-format support and an emphasis on hackability. Currently, Breezy has built-in support for the Git and Bazaar file formats and network protocols. GPLv2 licensed.
FlatGitHub or Flat View is a simple tool for exploring flat data files in GitHub repositories. Part of the Flat Data project (formerly GitHub OCTO), mentioned in Git Rev News Edition #75 (under old URL) and Edition #96, which in turn was based on the “git scraping” approach pioneered by Simon Willison, mentioned in Git Rev News Edition #82. See the example of flat-demo-bitcoin-price.
AllSpice.io is a Git platform for hardware developers (named after SPICE (“Simulation Program with Integrated Circuit Emphasis”), a general-purpose, open-source analog electronic circuit simulator). No free tier.
typos is a source code spell checker, which finds and corrects spelling mistakes in source code; intended to be fast enough to run on monorepos and have few false positives, so it can safely run unassisted, for example on PRs. Written in Rust.
- Mentioned in Perl Advent Calendar 2023 - Elves Versus Typos.
dat is a tool for peer-to-peer sharing & live synchronization of files via command line. Part of the dat-ecosystem. You can use the dat command line tool to share files with version control, back up data to servers, browse remote files on demand, and automate long-term data preservation. Written in JavaScript for running with Node.js.

Releases

Gerrit Code Review 3.9.1
GitHub Enterprise 3.11.2, 3.11.1, 3.10.4, 3.9.7, 3.8.12, 3.7.19, 3.11.0
GitLab 16.7, 16.6.2, 16.5.4, 16.4.4, 16.6.1, 16.5.3, 16.4.3
GitKraken 9.11.0
GitHub Desktop 3.3.6
Sourcetree 4.2.6

Credits

Git Rev News Edition 105 (November 30th, 2023)

chriscool — Thu, 30 Nov 2023 11:06:51 +0000

Git Rev News: Edition 105 (November 30th, 2023)

Welcome to the 105th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of October 2023 and November 2023.

Discussions

General

Git participates in Outreachy’s December 2023 to March 2024 round

Achu Luma will work on the “Move existing tests to a unit testing framework” project. They will be mentored by Christian Couder.

Congratulations to Luma for being selected!

Thanks to GitLab for sponsoring this Outreachy internship! Thanks also to the other contributors who applied and worked on micro-projects, but couldn’t be selected! We hope to continue to see you in the community!

Reviews

[PATCH v2 0/2] Prevent re-reading 4 GiB files on every status

In May 2022 Jason Hatton sent an email to the mailing list about the fact that any file of a size that is an exact multiple of 8GiB makes Git extremely slow on the repository.

He said that he had already opened an issue about this on the Git for Windows issue tracker where Jason, Philip Oakley, brian m. carlson and Johannes Schindelin, alias Dscho, had already discussed the issue.

Git uses an uint32_t type, a 32 bit long unsigned integer, for storing the file size in the index. This rolls over if the value is greater than 2 to the power 32, so with file sizes over 4GiB. When the size is exactly 4GiB or a multiple of it, like 8GiB, the rollover makes it zero.

A zero file size in the index has a special meaning for Git, though. It tells Git that the file needs to be hashed again. Hashing a file is supposed to reset its file size in the index to a non-zero value, but with a 4GiB file size the rollover happens and the file size is still zero. So the hashing will be performed again and again by many different Git commands, making Git very slow.

Jason proposed, as a solution to this problem, to detect when the rollover would happen, and in that case set the size to 1 instead of zero.

Junio C Hamano, the Git maintainer, replied to Jason confirming the issue and explaining it a bit more in detail. Jason and Junio then discussed the issue a bit more, while Jason tested locally his suggested fix and proposed to send a real patch to fix the issue.

René Scharfe then chimed into the discussion asking if a value other than one would be better and would avoid other possible issues. Philip Oakley replied to René suggesting using 0x80000000 instead of 1 when the rollover is detected. This would make it easier to detect “almost all incremental and decremental changes in file sizes”, as the file size in the index helps detecting file changes.

Jason and Philip discussed the issue a bit more and agreed that using 0x80000000 only for exact multiples of 4GiB would likely be the best solution.

Philip and Carlo Marcelo Arenas Belón also tried to help Jason properly submit a patch to the mailing list.

Jason then sent a patch to the mailing list with the changes and explanation that had been discussed. Torsten Bögershausen, Philip and Junio reviewed it, and suggested some improvements. Junio especially requested some tests to be added.

After some discussions with Jason to clarify what should be improved, Jason sent another version of his patch.

It looked like Jason found an issue with the patch due to using 0x80000000 instead of 1. René and Philip discussed it with Jason, but there was no clear conclusion. It wasn’t even clear if there was an issue at all. But anyway the work on this stopped for more than one year.

Fortunately a few weeks ago, brian m. carlson sent a new version of Jason’s patch along with another patch adding tests.

These patches were reviewed by Eric Sunshine, Jeff King, alias Peff, Junio and Jason. After some discussions it appeared that the patches were good enough for Junio, so he decided to apply a small change and then merge them. This issue is therefore fixed in Git 2.43.0 released on November 20th.

Developer Spotlight: Alexander Shopov

Who are you and what do you do?

I am Alexander Shopov - a backend engineer in the Amsterdam office of Uber working on money related systems. I am a long time translator of FOSS software to Bulgarian - I am coordinating translations of GNOME, Translation Project and many GNU modules. Bulgarian is an Eastern South Slavic language written in the Cyrillic alphabet.
What would you name your most important contribution to Git?

I made and now maintain the Bulgarian translation of the text interface of Git, Gitk, and Git Gui.
What is the typical workflow of a contributor engaged in Git translation?

There are 19 translations of the text interface of Git, and only 13 of them are above 80%, so I am not sure about “typical”. It is a fairly standard workflow for a FOSS project.

Generally one needs to do the following:
1. Read the translator-targeted README.md in the po directory
2. Sync pace with the calendar of Git releases
3. Use the l10n coordinator repository maintained by Jiang Xin who makes sure translations get integrated upstream.
Currently the translation is a bit above 5500 messages, which is about 40k words, 250k of characters, or about 150 pages of text. It can be intimidating for a new translator. But you can definitely make it: be patient and translate some messages every release, merge, publish and repeat. Even better though harder is getting more than one person translating.
Do you contribute to Git in ways other than providing translation? If so, could you elaborate about them?

Sadly not that much. On rare occasions I improve messages and mark strings for translations. Perhaps that will be the way I contribute unless I find a mentor and something that I find particularly interesting and important for me. So if anyone is willing to mentor me, especially in making large repos faster - ping me. I can be a competent tester at least.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Due to its enormous success, Git is being used on humongous code bases with a crazy number of files, directories, commits and branches. Working with repos larger than 10GB can be a bit slow. Improving the experience would be a great thing.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Backwards compatibility is massively important and I am thankful developers and users are all invested in this.

If we treat this as a hypothetical question, there are 3 things to Git:
- the command-line interface
- the wire protocol
- the storage format
The command-line interface is gradually being improved. The wire protocol is also a place where there are workarounds for versioning. The storage format however is another (quite conservative and public) API. I would remove the old versions and try to design it targeting projects that are 10-100 times larger than the Linux kernel first. In for a penny, in for a pound. If we break things, let us break them so hard that bards will sing songs about us!
What is your favorite Git-related tool/library, outside of Git itself?

I mainly use command line git plus gitk and git-gui. I do like using the meld diff tool when I work on translations.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

The initial getting to 100% translated messages was a challenge. I decided that I should translate Git around December 2013. That was around 2200 messages at that time and it took me about 3 releases of Git to reach 100%. Getting to 100% was immensely hard, rewarding and memorable. Afterwards keeping the translation at 100% was much easier.
Is there something you feel could be done to ease the life of translators?

The terminology glossary of Git is much larger than 7 years ago, and we (the translators) should actually update git://repo.or.cz/git-gui.git::po/glossary and merge it in Git.
What is your advice for people who want to start Git development? Where and how should they start?

I don’t know to be honest. If I knew I may have started already.
If there’s one tip you would like to share with other Git developers, what would it be?

That would be the tip of master two years in the future. On a more serious note - perhaps more tools for migration out of the still existing proprietary version control systems would be helpful.

Other News

Various

Highlights from Git 2.43 by Taylor Blau on GitHub Blog. Those include new git repack tricks (including adjusting sparse clone filters), nicer looking reverts of reverts with git revert, fixed interaction between --subject-prefix and --rfc in git format-patch, custom log format options that simulate the decorations, etc.
Gitea Cloud: A brand new platform for managed Gitea Instances, designed for enterprise organizations to set up and run their own Gitea instances more easily and efficiently.
Announcing DoltgreSQL by Daylon Wilkins on DoltHub Blog.
- Git-for-Data, Version-Controlled Database Dolt Gets PostgreSQL-Flavor by Sergio De Simone on InfoQ.
- Dolt, a version-controlled database, was first mentioned in Git Rev News Edition #62.
An Interesting CMS With Version Control is Now Open-Source! by Sourav Rudra on It’s FOSS News (it’s TinaCMS).
Introducing the Space Git Subtree by Ilia Afanasiev on The Space Blog (where Space is JetBrains’ code collaboration platform).
Developers can’t seem to stop exposing credentials in publicly accessible code by Dan Goodin on Ars Technica, and
Uncovering thousands of unique secrets in PyPI packages by Tom Forbes on GitGuardian Blog.
14 years of JGit/EGit Code Reviews migrated to GerritHub by Luca Milanesio on GerritForge Blog.

Light reading

How I (kind of) killed Mercurial at Mozilla by Mike Hommey (author of git-cinnabar, Git remote helper to interact with Mercurial repositories).
Julia Evans continues the series of articles about Git (started in Git Rev News #103 with In a git repository, where do your files live? and Git Rev News #104 with Some miscellaneous git facts); currently there are the following additional posts: Confusing git terminology, git rebase: what can go wrong?, How git cherry-pick and revert use 3-way merge, and git branches: intuition & reality.
- Julia Evans (@b0rk@jvns.ca) asked about a read-only FUSE filesystem for a Git repository where every commit is a folder and the folder contains all the files in that commit on Mastodon, so this series may continue (so far it led to very experimental git-commit-folders tool from her, and GitMounter from Jordan Rose being made public).
- See also Pain in the dots by Matthew Brett (part of Notes and tutorials on git), about the confusing difference in how two-dot and three-dot notations behave in git log and git diff, as an addition to the Julia Evans’ article about confusing Git terminology, the .. and … section.
How I teach Git by Thomas Broyer on his blog (also on DEV.to). Inspired by Julia Evans’ (renewed) interest in Git and her questions on social networks.
Stacked Diffs (and why you should know about them) by Gergely Orosz in The Pragmatic Engineer blog. Another article about Stacked Diffs can be found in Git Rev News Edition #44.
- Compare and contrast Ship / Show / Ask: A modern branching strategy mentioned in Edition #79.
Why I Prefer Trunk-Based Development by Koen van Gilst on his blog.
- See also Patterns for Managing Source Code Branches in Git Rev News Edition #73.
A bit controversial Dependencies Belong in Version Control (even if it’s not practical today due to Git’s limitations) by Forrest Smith on his blog.
Managing My Resume with Git: A Version Control Approach by Bui Dang Binh (dunkbing) on DEV.to.
See the History of a Method with git log -L by Caleb Hearth on his blog; the post lists also a few his other articles about Git:
- Stash only what git commit wouldn’t commit.
- Ignore refactoring commits in git blame.
- Use your SSH key to sign commits.
  - See also, for example, Signing Git Commits with SSH Keys from Git Rev News Edition #83.
Why Git blame sucks for understanding WTF code (and what to use instead) by Tekin Süleyman (2020); the author recommend “pickaxe” search with git log -S and git log -G, or searching commit messages with git log --grep.
How to Resolve Merge Conflicts Using the Merge Editor Feature on VS Code by Ayu Adiati on Ayu’s Notes On Blog (also on DEV.to, as part of larger Open-Source Series’ Articles).
The Ultimate “git nah” Alias to throw away current changes, untracked files and rebase state, by Paul Redmond on Laravel News.
Understanding Git: The history and internals by Kenneth DuMez on the Graphite Blog (more about history and internals than about understanding Git). See also:
- GitHistory page in the archives of Git SCM Wiki,
- The Git Parable, by Tom Preston-Werner (2009) - the ideas behind the architecture of Git; covered in Git Rev News #30,
- Will Hay Jr.’s The Architecture and History of Git: A Distributed Version Control System, mentioned in Git Rev News #46,
- The History of Git: The Road to Domination in Software Version Control referenced in Git Rev News #60.
Tracking SQLite Database Changes in Git with an appropriate textconv gitattribute, by Garrit Franke on Garrit’s Notes.
GitHub’s all-in bet on AI may overlook Git by Matt Asay on InfoWorld.
🙏 Please Add .gitattributes To Your Git Repository by Carl Saunders on DEV.to (2020).
- A .gitattributes file can be used to improve language detection on GitHub, which is using the Linguist library.

Easy watching and listening

Git Training playlist of 45 short YouTube videos by Joost De Cock provides Git training materials for people who would like to understand how Git works rather than try to memorize all of its commands without knowing what they do.
The Real Python Podcast: Episode 179: Improving Your Git Developer Experience in Python

Git tools and sites

gitattributes.io is a service to generate .gitattributes files, similar to gitignore.io.
githistory.xyz is a service that allows to quickly browse the history of files in any Git repo (from GitHub, GitLab, Bitbucket). Also available as Chrome, Firefox, and Visual Studio extensions, and as git-file-history command line tool (in Node.js). Mentioned in passing in Git Rev News Edition #48.
Josh Branchaud (jbranchaud) collected a list of Today I Learned (TIL) tips about Git.
lei is a command-line tool for importing and searching email, regardless of whether it is from a personal mailbox or a public-inbox instance, like public-inbox.org or lore.kernel.org.
Warning: lei is still in its early stages and may destroy mail.
- See also lore+lei: part 1, getting started article by Konstantin Ryabitsev (2021).
git-fame: Pretty-print Git repository collaborators sorted by contributions (includes computing code survival). Written in Python.
git-fame-rb is a command-line tool that helps you summarize and pretty-print collaborators, based on the number of contributions. The statistics are mostly based on the output of git blame (counting surviving lines). Written in Ruby.
GQL (Git Query Language) [repo] is a SQL-like language to perform queries on .git files, with support for many SQL features such as grouping, ordering and aggregation functions.
You can find more in How I Created a SQL-like Language to Run Queries on Local Git Repositories article by Amr Hesham on freeCodeCamp.
See also the following tools:
- Gitana: SQL-based Project Activity Inspector (repo archived in 2022), first mentioned in Git Rev News Edition #7.
- gitbase: SQL interface to Git repositories, written in Go; (last release from 2019, homepage is not working), first mentioned in Git Rev News Edition #48.
- git-history is a tool for analyzing Git history using SQLite (last release in 2021), first mentioned in Git Rev News Edition #82.
- MergeStat enables SQL queries for data in Git repositories (and related sources, such as the GitHub API). There is also the mergestat-lite command line tool, which runs SQL queries against local Git repositories. First mentioned in Git Rev News Edition #82. Actively developed, mergestat-lite is written in Go.
GibleFS is a toy project that maps a Git repository to a virtual filesystem, which then can be used to access the repository at any given commit. Written in Rust, does not seem to be actively developed.
The Git/fs binary in Git9 (Git client for Plan 9 non-POSIX filesystem) serves repository history as a file system.
gitfs is a FUSE file system that fully integrates with Git. You can mount a remote repository’s branch locally, and any subsequent changes made to the files will be automatically committed to the remote. Written in Python, last release in 2019.
- Note: that is not the only project named gitfs or git-fs.
SlothFS is a FUSE filesystem that provides light-weight, lazily downloaded, read-only checkouts of manifest-based Git projects. It is intended for use with Android. Written in Go, repository archived in 2022.
GitMounter is a toy FUSE browser for Git repos based on Suffusion. Requires FUSE, libgit2, pkg-config, and Swift installed. Written in Swift.

Releases

Git 2.43.0, 2.43.0-rc2, 2.43.0-rc1, 2.43.0-rc0, 2.42.1
Git for Windows 2.43.0(1), 2.43.0-rc2(1), 2.43.0-rc1(1), 2.43.0-rc0(1)
GitLab 16.6, 16.5.2, 16.5.1, 16.4.2, 16.3.6
Gerrit Code Review 3.6.8, 3.7.6, 3.8.3, 3.9.0-rc6
GitHub Enterprise 3.11.0
GitKraken 9.10.0
GitHub Desktop 3.3.5
Tower for Windows 5.2
Tower for Mac 10.2

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Alexander Shopov, Luca Milanesio, Bruno Brito, and Štěpán Němec.

Git Rev News Edition 104 (October 31st, 2023)

chriscool — Tue, 31 Oct 2023 11:06:51 +0000

Git Rev News: Edition 104 (October 31st, 2023)

Welcome to the 104th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of September 2023 and October 2023.

Discussions

General

Git Virtual Contributor’s Summit 2023

A virtual summit happened on September 26th and 27th, where the contributors discussed topics that they had previously voted on. Taylor Blau, who organized the summit, polished and then sent the notes that were taken during the summit to the mailing list.

Reviews

[PATCH] diff –stat: add config option to limit filename width

Dragan Simic sent a patch to the mailing list that added a new diff.statNameWidth=<width> configuration option. The goal with this option was to make it possible to limit the width of the filepath part of the “stat” output of git diff commands.

For example, the “stat” output of a git diff command contains lines like this:
```
path/to/file.txt                         | 11 +++++++--
```
where the “filepath” part, also called “name” or “filename” part, of that output is path/to/file.txt and the “graph” part is 11 +++++++--.

There were already a diff.statGraphWidth=<width> configuration option to limit the width of the graph part, and also --stat-name-width=<width> and --stat-graph-width=<width> command line options to limit the width of the name and graph part, respectively. So it was logical to add the missing configuration option.

These options are especially useful for people using very large terminals, to prevent “stat” output from using a lot of columns.

The new diff.statNameWidth=<width> was designed to be ignored by git format-patch in the same way as diff.statGraphWidth=<width>, because that command already respects the traditional 80-column standard.

Before sending this patch, Dragan had sent an RFC email asking if such a patch would be accepted, which led to an interesting discussion between him and Junio Hamano, the Git maintainer, about the fact that we often cannot promise anything about a hypothetical patch before actually seeing it on the mailing list.

Junio reviewed the actual patch and wondered if it would be possible to specify contradictory values for the whole width on one side and the “name” and “graph” width on the other side. He also suggested creating a helper function to initialize all the variables that contain the values of the configuration options for the different parts, as the code initializing those variables was duplicated in the code of many Git commands.

Dragan replied that the diff code already performed “a reasonable amount of sanity checks and value adjustments”. He wondered if warnings should be emitted in case of contradictory settings though.

Dragan then agreed that refactoring the code that initialized the variables would be nice, but he proposed to do it after the current patch would have been merged.

Junio and Dragan agreed with doing the refactoring later and discussed a bit deeper if more changes were needed in this patch, but it appeared that it could be merged as is, and so it was.

A few days later Dragan sent a patch to refactor the code that initialized the variables. Junio reviewed it and suggested some improvements, which Dragan implemented in a second version of the patch.

This second version was also reviewed by Junio and then merged.

Other News

Various

New book “Boost Your Git DX” by Git contributor Adam Johnson, covering tools and configurations to improve your command line workflow.
Git 2.42 release: Here are four of our contributions in detail by Christian Couder on GitLab Blog.
- Highlights from Git 2.42 link can be found in Git Rev News Edition #102.

Light reading

Some miscellaneous git facts by Julia Evans on her blog. The facts are:
- the “index”, “staging area” and “--cached” are all the same thing
- the stash is a bunch of commits
- not all references are branches or tags
- merge commits aren’t empty
Why Git is hard by Nick Eff on his Roadrunner Twice Dreamwidth’s journal, in response to Julia Evans ending her StrangeLoop 2023 keynote talk with “I still don’t know why Git is hard.”
- There is some discussion on the programming.dev Lemmy instance about this post.
- Various attempts to make Git or version control easier include Gitless - first mentioned in Git Rev News Edition #20, Jujutsu - mentioned in #85, and EasyGit (eg) - seems not to be actively developed.
Investigating Git History by Kristian Lumme on Tower’s blog.
Measuring Git performance with OpenTelemetry by Jeff Hostetler on GitHub Blog. It describes how to use open source Trace2 receiver component (trace2receiver) and OpenTelemetry to capture and visualize telemetry from your Git commands.
What is in that .git directory? by Abin Simon on meain/blog.
Versioning data in Postgres? Testing a git like approach by Samuel Bodin on his Specfy Blog.
Organizing multiple Git identities using .gitconfig includes, by Garrit Franke on Garrit’s Notes blog.
Linux Fu: Deep Git Rebasing by Al Williams on Hackaday.
Git: Rewriting History 101 by Matheus Tavares (2022).
How to split off an older copy of a file while preserving git line history by Raymond Chen on Microsoft’s The Old New Thing DevBlog.
- His older article on how to duplicate a file while preserving git line history was mentioned in Git Rev News Edition #51.
Embracing Database Deployments in CI/CD Practices with Git by Vanessa Fox from PlanetScale on TheNewStack.
- An article about PlanetScale branching support for MySQL was mentioned in Git Rev News Edition #99, while PlanetScale as solution was mentioned in set of article about databases and versioning in Git Rev News Edition #82.
TypeScript Monorepo with NPM workspaces by Dmitry Kudryavtsev on yield code(); blog.
The “Schrödinger’s tree object”: is it there or not?: Matheus Tavares finds about the hard-coded empty tree object (2022).

Git tools and sites

gittuf provides a security layer for Git using some concepts introduced by The Update Framework (TUF). Among other features it handles key management for all developers on the repository, allows you to set permissions for repository branches, tags, files, etc.
gittuf is a sandbox project at the Open Source Security Foundation (OpenSSF) as part of the Supply Chain Integrity Working Group. It is currently in alpha. Written in Go.
trace2receiver project is a trace receiver component library for an OpenTelemetry Custom Collector daemon. It receives Git Trace2 telemetry from local Git commands, translates it into an OpenTelemetry format, and forwards it to other OpenTelemetry components. Written in Go as a static library component that must be linked into an OpenTelemetry Custom Collector.
git-bundle-server is a web server & management CLI to host Git bundles for use with Git’s “bundle URIs” feature. By running this software, you can self-host a bundle server. Written in Go, under active development. Installation on Windows is currently unsupported.
Awesome GitHub Alternatives is a list of alternatives to GitHub that by default offer Git management in some way. All self-hosted options are free and open source, with GPL-compatibile licenses. Not exhaustive.
src (Simple Revision Control) is RCS/SCCS reloaded with a modern UI, designed to manage single-file solo projects kept more than one to a directory. Use it for FAQs, ~/bin directories, config files, and the like. Written in Python.
- Mentioned in passing in Git Rev News Edition #46.

Releases

GitHub Enterprise 3.10.3, 3.9.6, 3.8.11, 3.7.18
GitLab 16.5
Bitbucket Server 8.15
GitKraken 9.9.2, 9.9.1, 9.9.0
GitHub Desktop 3.3.4
TortoiseGit 2.15.0
git-credential-oauth 0.11.0

Credits

Git Rev News Edition 103 (September 30th, 2023)

chriscool — Sat, 30 Sep 2023 11:06:51 +0000

Git Rev News: Edition 103 (September 30th, 2023)

Welcome to the 103rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of August 2023 and September 2023.

Discussions

General

Git participated in GSoC (Google Summer of Code) 2023

The following contributors have successfully passed their final evaluation and published a final report:
- Shuqi Liang worked on the More Sparse Index Integrations project. She was mentored by Victoria Dye. The final report can be found on her website.
- Kousik Sanagavarapu worked on the Unify ref-filter formats with other –pretty formats project. He was co-mentored by Christian Couder and Hariom Verma. The final report can be found on his website.
Congratulations to these contributors and their mentors!

Support

Fetching too many tags?

Ronan Pigott noticed that when he fetched from some repos, for example from the “Linux Stable” repo on kernel.org, most of the time seemed to be spent transferring tags from the remote to the client.

When his local repo was up-to-date and git fetch was used with --no-tags (or its -n shortcut), it took less than 0.4 seconds versus more than 1.7 seconds without it.

He asked if there was a reason for this seemingly useless transfer of tags even when the remote didn’t have to send any commit.

Peff, alias Jeff King, replied that “this is how the Git protocol works”. He explained that the server only lists all the refs it knows about, and expects the client to select the refs it wants among them. “Only the client knows what it already has.” For example, there could be new tags on the server pointing to commits that the client already has.

Peff also mentioned that in recent Git versions an extension of the Git protocol allows clients to list only the refs they are interested in, so that the server can send “a much smaller ref advertisement”.

Ronan asked if Peff was talking about the --negotiation-tip option, as some tests using this option didn’t result in better performance.

Peff replied that --negotiation-tip was only useful when there are commits that should be transferred. When histories on the client and the server have diverged, this option helps them find a common commit that can be the base for the commits that will be transferred.

Peff said the extension of the Git protocol he was talking about are “ref-prefix” lines in Git’s “v2” protocol, which is the default protocol since Git v2.29. This protocol allows the client to speak first and specify which ref prefixes it’s interested in with these “ref-prefix” lines.

Setting the GIT_TRACE_PACKET to 1 allows one to see the packets exchanged between the client and the server, especially the “ref-prefix” lines when for example git fetch --no-tags origin master is launched using a recent Git, or the “have” and “want” lines when client and server have to negotiate a common commit.

Ronan tested Peff’s suggestions and thanked him as he then understood why the tag advertisement was useful.

Other News

Various

Critical GitHub Vulnerability Exposes 4,000+ Repositories to Repojacking Attack on The Hacker News. The vulnerability was caused by a race condition within GitHub’s repository creation and username renaming operations.
Nx lands $16M to build ‘monorepo’ tools for software devs by Kyle Wiggers on TechCrunch. The funding will be used to expand Nx’s fully managed product, Nx Cloud, a replacement for existing continuous integration tools, such as Jenkins, with first class monorepo support.
Harness launches Gitness, an open-source GitHub competitor by Frederic Lardinois on TechCrunch.

Light reading

In a git repository, where do your files live? by Julia Evans on her blog.
Don’t create .gitkeep files, use .gitignore instead by Adam Johnson.
Signing Commits in Git, Explained by Scott Chacon on GitButler Blog.
Selecting the Right Git Merging Strategy: Merge Commit, Squash and Merge, or Rebase and Merge by Akash Rajpurohit on his blog.
Drop git pull for fetch and rebase by Yftach Herzog on RedHat Developer Blog, arguing that git fetch followed by git rebase is a safer alternative (with a feature branch workflow).
Advanced Git Commands and Workflows: A Comprehensive Guide for Developers by Matías Hernández Arellano for Documatic on DEV.to; covers interactive rebase, cherry-picking, git bisect, reflog, git blame, and various Git collaboration workflows.
Git Delta is a Syntax Highlighting Pager for git, diff, and grep output by Paul Redmond on Laravel News blog. Delta was first mentioned in Git Rev News Edition #86; there is a link to another article about Delta in Edition #102.
- There is also a Delta command-line diff tool implemented in Go, with a dead homepage (archive), mentioned in Git Rev News Edition #9.
Git-Based Software Development Life-Cycle by Kris considers whether tools like git-appraise, git-issue, and git-bug that store their information, history, and artifacts directly in the repository can replace development tools such as Jira (planning, issue tracking), Confluence (wiki, documentation platform), Bamboo (CI/CD server), Artifactory (storing Docker images and CI/CD artifacts), and Gerrit (code review).
- Git Rev News Edition #43 includes a list of similar tools and links related to them.
- git-appraise was first mentioned in Git Rev News Edition #11.
Delving Deeper into Gitamic: Power and Flexibility Beyond Statamic’s Built-In Git Features by Eric L. Barnes on Laravel News blog. Gitamic is a premium Statamic CMS add-on that allows you to take full control of your Git workflow from within your CMS.
GitLab CI: 10+ Best Practices to Avoid Widespread Anti-patterns by Benoit COUETIL for Zenika on DEV.to.
Fossil Versus Git on Fossil Wiki.

Easy watching

The Git Parable: a different approach to understanding Git, a talk by Johan Herland for Tweag, based on Tom Preston-Werner’s essay of the same name (2009) covered in Git Rev News #30.

Git tools and sites

git-credential-azure is a credential helper that authenticates to Azure Repos.
git-vain is a tool to generate vanity hashes quickly; it can be used for example to make SHA-1 hash of the HEAD begin with c0ffee. Written in Rust. Other similar tools:
- git-vanity-sha, written in Ruby, mentioned in Git Rev News Edition #39.
- ~~git-sham~~ (no longer available); first mentioned in Git Rev News Edition #4.
git-issue is a minimalist decentralized issue management system based on Git, offering (optional) bidirectional integration with GitHub and GitLab issue management. Written as set of shell scripts.
- Similarly named git-issues, written in Python, was mentioned in Git Rev News Edition #43.
Cup is an extensible server for building automation around introspection and contributions to Git and SCMs like GitHub. It is an active experiment into the benefits of managing an API over Git. Written in Go by Flipt - the open source, self-hosted feature flag solution.
- Flipt itself was mentioned in Git Rev News Edition #96.
Gitness by Harness is an open-source code hosting and pipeline engine, with source control management, Continuous Integration and Continuous Delivery, that can be easily installed using Docker. Written in Go. Can be considered the next generation of Drone.
Gitopia is the next-generation Decentralized Code Collaboration Platform fueled by a decentralized network and interactive token economy. It is designed to optimize the software development process through collaboration, transparency, and open source incentivization. You need to have a supported wallet with sufficient LORE tokens to use Gitopia’s services. Pushing changes to Gitopia is done with the help of git-remote-gitopia helper.
- Compare with git-ssb (see git-ssb-intro guide): decentralized git repo hosting and issue tracking on secure-scuttlebutt (SSB), mentioned in Git Rev News Edition #26 and #40.
- Contrast with ForgeFed (formerly GitPub), a federation protocol for forge services (ActivityPub extension), mentioned in Git Rev News Edition #69 and #95, and various projects in different stages of development that implement it: Vervis, Forgejo, ForgeFlux, and Forgefriends.
Mermaid, a JavaScript-based diagramming and charting tool that can be embedded in Markdown documents (which is supported on GitHub), now supports Gitgraph Diagrams.

Releases

Git for Windows 2.42.0(2)
Gerrit Code Review 3.6.7, 3.7.5, 3.8.2
GitHub Enterprise 3.10.2, 3.10.1, 3.9.5, 3.8.10, 3.7.17, 3.6.19, 3.10.0, 3.9.4, 3.8.9, 3.7.16, 3.6.18
GitLab 16.4 16.3.4 and 16.2.7, 16.2.6, 16.3.3, 16.3.2, 16.3.1, 16.2.5, and 16.1.5
Bitbucket Server 8.14
GitKraken 9.8.2, 9.8.1, 9.8.0
GitHub Desktop 3.3.3, 3.3.2, 3.3.1, 3.3.0
Tower for Windows 5.1
git-credential-azure 0.2.3
git-credential-oauth 0.10.1

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Adam Johnson, Bruno Brito, Mirth Hickford and Štěpán Němec.

Git Rev News Edition 102 (August 31st, 2023)

chriscool — Thu, 31 Aug 2023 11:06:51 +0000

Git Rev News: Edition 102 (August 31st, 2023)

Welcome to the 102nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of July 2023 and August 2023.

Discussions

Support

Git Privacy

Nick, alias Nicholas Johnson, asked on the Git mailing list if it would be possible to implement an integrated feature in Git, perhaps a config option, to obfuscate the committer and author timestamps that are stored in commits when they are created.

Nick is the creator of Git Privacy which is a repository containing instructions in a README.md file that already helps developers obfuscate Git timestamps, and also explains why it can be a good idea to do so.

The instructions suggest setting the GIT_AUTHOR_DATE and GIT_COMMITTER_DATE environment variables when committing, so that the timestamps in these variables are recorded instead of the current date, time and timezone.

Nick thought that using such environment variables or other not fully integrated mechanisms like Git hooks was too cumbersome and asked for ideas or feedback about how to improve the situation.

Junio Hamano, the Git maintainer, replied to Nick, saying that his opinion was that it might not be worth implementing an integrated feature, as using such a feature removed “half the value of keeping your work in [a] source code management system”. Especially it would make it harder to refute possible claims that the source code contained stolen proprietary IP (Intellectual Property).

Nick replied that he conceded it might not be worth it to implement his original suggestion. He said that having Git automatically converting local time to UTC in the timestamps it records could still be useful to avoid leaking the developer’s time zone. He pointed to a Gerrit issue about this.

Junio replied that he still thought it wasn’t worth the effort as there was not enough reason to go against Git’s initial design to store the timezone.

Nick replied to Junio saying that storing the timezone revealed private information about developers without much gain, and that a config option could let users decide about doing this or not.

This led to a separate sub-thread where Nick and Jason Pyeron started to design a --privacy=option1,option2 with corresponding config variables to change the timezone, specify a date precision, etc. brian m. carlson said he would support timezone and timestamp tweaking options and made some technical suggestions too.

René Scharfe chimed in on the main thread saying that “timezone and timestamps are personal data, which may only be collected and processed for a lawful purpose according to the GDPR”, referring to the European Union’s General Data Protection Regulation. So he thought that the user should be able to control if that data should be stored or not, and it was a usability issue if he could not easily do that. He also noticed that git commit already has a --date=<date> option to change the author date and a --signoff option for adding Signed-off-by: Author Name <author@example.com> trailers. He concluded by saying “adding config options for controlling timestamp granularity is hard to say no to”.

Nick replied that he was asking for this feature for moral reasons not for legal ones. He took the example of the I2P project which is a layer on top of Internet to protect people’s activity and location, saying that most developers of the project don’t want their timezones leaked as they are known only under pseudonyms.

Junio replied to René saying that the --date=<date> option had good reasons to exist. For example, the committer might be relaying somebody else’s changes, or a system clock might have an issue. He also thought that the existing two environment variables are the right place to draw the line, as Git developers shouldn’t be pretending to be security engineers and invent their own time obfuscating mechanisms.

In another email, Junio explained in more detail why it’s more important to be able to tweak the author timestamp than the committer timestamp. He also repeated that two environment variables were a good place for other security minded people to build on a quality “privacy enhancing date command” that could also be used outside the Git context.

Junio replied to himself saying that a “–useless-time” option, or a “core.uselesstime” configuration variable to make timestamps only use UTC and be otherwise nearly meaningless could be OK though, as they wouldn’t have “privacy” in their name and wouldn’t pretend to be a quality privacy feature. He laid out how such a feature could work, and noticed that features like git log --since=... wouldn’t then be expected to properly work.

Nick agreed that such a feature shouldn’t use “privacy” in its name, and said that Junio’s proposed feature would satisfy the privacy use case he was interested in, and that he didn’t want more than that.

Theodore Ts’o then chimed in to point out that “someone still might be able to figure out information from when a branch gets pushed to a git repo”. He mentioned that for example GitHub, GitHub actions and integration systems could also leak information about when users are active.

Nick replied to Ted saying that protecting privacy had to start somewhere, even if not all the tools were already doing it.

Future will tell if someone will actually implement something along the lines that have been discussed, and whether it will be a “privacy enhancing date command” usable outside the Git context, or an option integrated into Git.

Developer Spotlight: Calvin Wan

Who are you and what do you do?

My name is Calvin Wan and I’m a Software Engineer on the Git Core team at Google.

I also enjoy playing poker, volleyball, and ping pong. I play the World Series of Poker Main Event every year and one of these years I’m hoping to make the final table 😄
What would you name your most important contribution to Git?

I’m hoping my in-flight series for a Git Standard Library will become my most important contribution to Git…at least for now 😄
What are you doing on the Git project these days, and why?

Currently working on getting Git Standard Library merged – to summarize it will serve as the foundation for other libraries in Git to be built off of. When we first embarked on this journey towards libification, we had many reasons for doing so, most of which Emily captured in the initial proposal.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Old style submodules. Submodule development is already difficult to work on, and having extra bits and pieces in the codebase that exist for the sole purpose of not breaking old style submodules added an extra layer of complexity I wish I didn’t have to reason about.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Attending Git Merge 2022! I enjoyed meeting the people I had been interacting with on list – putting a face to the name was particularly exciting. I also enjoyed the discussions at the Contributor Summit and the talks that followed.
What is your toolbox for interacting with the mailing list and for development of Git?

I develop using VSCode and send my patches with git format-patch and git send-email. For patches upstream, I use b4 am + git am to test locally. When I reply to patches I use a script I modified from Jonathan Tan to set up the replies for git send-email. For simple replies and emails, I use Gmail’s plaintext mode.
What is your advice for people who want to start Git development? Where and how should they start?

I think there are plenty of good resources out there that others have probably mentioned before (Pro Git book, MyFirstContribution, git-mentoring list), but the one suggestion I would have is spend less time worrying about getting the right setup and spend more time getting your patches to list!

Other News

Various

Highlights from Git 2.42 by Taylor Blau on GitHub Blog. Those include faster object traversals with reachability bitmaps, excluding references by pattern in git for-each-ref, preserving precious objects from garbage collection via gc.recentObjectsHook, and other changes.
Git 2.42 Released With Less Warnings For SHA-256 Usage by Michael Larabel on Phoronix.
GitLab Gitaly project now supports the SHA-256 hashing algorithm by John Cai on GitLab Blog.
- Gitaly is an RPC interface to Git used by GitLab, first mentioned in Git Rev News Edition #24.
Sourceware 25 Roadmap: roadmap for the next 25 years on [almost] the 25th anniversary (Sourceware came online on 6 September 1998).
- Sourceware service was first mentioned in Git Rev News Edition #88.
Lazygit Turns 5: Musings on Git, TUIs, and Open Source by Jesse Duffield on his Pursuit Of Laziness blog.
- lazygit is a simple [windowed] terminal UI for Git, written in Go. It was first mentioned in Git Rev News Edition #42; you can find links to other articles about this tool in Edition #61 and #81.

Light reading

7 Git Mistakes a Developer Should Avoid by Bruno Brito on Tower Blog, describing why some habits – committing unrelated changes together, writing bad commit messages, not using .gitignore, leaving outdated merged-in branches, using force push in a shared repository, storing API keys and other secrets in a repository, and storing large binary files – cause problems, and how to prevent them (often how to do it with the help of the Tower Git client).
Simplified: 8 Guidelines for Commit Message by Tito (titusnjuguna) on DEV.to.
Security in Code Reviews: Ensuring Secure and Robust Software Development by Jatin Sharma for Documatic, lists some common security vulnerabilities, presents a few examples of real-world incidents, and explains how to incorporate security into the code review process (and what the challenges are).
One Git Trick for Perfect Commits by Raman Nikitsenka (0ro) on his blog (and also on DEV.to). The trick to avoid “fix: …” commits littering history is to use git commit --fixup and git rebase --interactive --autosquash (before submitting changes).
Git Config Articles: Pragmatic Suggestions for Customizing Your Git Setup from Karl Stolley by Margaret Eldridge in The Pragmatic Programmers on Medium. It is a list of Git Config articles written by Karl Stolley for The Pragmatic Programmers.
Simplify Your Workflow 📈: A Guide to Standardizing Commit Messages with Husky 🐶 in Monorepos 📦 by Muhammad Harith Zainudin on DEV.to.
- Husky, a Git hook management tool, was first mentioned in Git Rev News Edition #63; you can find links to other articles talking about it in #87 and #89.
- The idea of Monorepos (using a single repository for the whole codebase) was first mentioned in Git Rev News Edition #4. You can find links to articles advocating for and against monorepos in Git Rev News Edition #47, and a list of pros and cons of monorepos in Edition #81. Monorepo.tools is a place where you can find information about monorepos and tools for handling them (this site was first mentioned in Git Rev News Edition #84).
You won’t believe how much time you will save with this Git pre-push hook by Ivan Morgillo on his blog, about integrating Git hooks with static code analysis tools, such as Detekt (a static code analyzer for Kotlin), for Android projects.
Git advanced (text) diff: .odt, .pdf, .doc, .xls, .ppt by Maxime Bréhin on Medium (2016) describes how to configure textconv gitattribute for those files.
IAMbic: Bridging the Gap Between IAM (Identity and Access Management) Changes and Version Control by Curtis Castrapel on Noq company blog. IAMbic detects IAM changes, whether you’re using Terraform, Cloudformation, or directly making changes via the AWS Management Console, and creates Git commits to represent the exact state of your IAM in a Git repository.
Delta: A new git diff tool to rock your productivity by Axel Navarro for Cloud(x); on DEV.to (posted on 16 Jul 2020, updated on 22 May 2022).
- Delta, a syntax-highlighting pager for git, diff, and grep output, was first mentioned in Git Rev News Edition #86.
Git Files Hidden In Plain Sight 🫥 by Tyler Cipriani on his blog, about some wonderful bad ideas, like storing data in a repository in a way that GitHub thinks it is empty.

Easy watching

Git Hidden Gems - Enrico Campidoglio - NDC Oslo 2023 (length: 59:11).
Talks about 04:15 pretty logs, 08:23 pretty diffs, 10:24 staging, 18:57 searching, 22:27 automation, 28:48 dot notation, 33:20 rebase onto, 38:24 reflog, and 45:44 rerere.
Pijul: Version-Control Post-Git • Pierre-Étienne Meunier • GOTO 2023: the presentation recorded at GOTO Aarhus 2023 (length: 50:10).
Pijul was first mentioned in Git Rev News Edition #9.

Git tools and sites

Git Tag Ops by Iterative.AI turns your Git repository into an Artifact Registry. Together with DVC (Data Version Control), GTO serves as a backbone for Git-based Iterative Studio Model Registry. GTO works by creating annotated Git tags in a standard format. Written in Python.
- DVC and GitOps were first mentioned in Git Rev News Edition #42.
Turtle is a graphical interface for version control intended to run on GNOME and the Nautilus file manager. Written in Python using GTK4 and libadwaita for the GUI, and pygit2 for interacting with Git, with Nautilus plugin support.
- See TortoiseGit, Windows Shell interface to Git, providing overlay icons showing the file status, and a powerful context menu for Git in a file manager. Tracked since Git Rev News Edition #57.
- Turtles, tortoises, and terrapins are common names used for animals from a taxonomical order of reptiles named Testudines.
Commit is a command palette-style Git client for blazing-fast commits. You open it with a keyboard shortcut, write your commit, and Commit will automatically detect which repo you’ve been working on. Written using the Tauri toolkit in TypeScript and Node.js for UI, and Rust for the backend. Inspired by TailwindUI’s Commit template.
GitButler (currently in alpha phase) is intended to be a Source Code Management system designed to manage your branches, record and backup your work, be your Git client, help with your code, etc.; focusing on everything after writing code in your editor and before sharing it on GitHub.
GQL (Git Query Language) is a query language with a syntax very similar to SQL, with a tiny engine to perform queries on Git repositories on the fly without the need to create database files or convert .git files into any other format. Written in Rust.
- Gitana, first mentioned in Git Rev News Edition #7, exports the data contained in one or more Git repositories to a relational database, relying on an incremental propagation mechanism that refreshes the database content with the latest modifications in Git repositories. Gitana has been archived in September 2022 and is not maintained anymore. Written in Python.
- gitbase, first mentioned in Git Rev News Edition #48, is a SQL database interface to Git repositories (on the fly), implementing the MySQL wire protocol. It can be used to perform SQL queries about the Git history and about the Universal AST (Abstract Syntax Tree) of the code itself. Was a part of now defunct source{d} Community Edition, still in alpha phase. Written in Go.
- MergeStat (demo) enables SQL queries for data in Git repositories (and related sources, such as the GitHub API). It allows you to ask questions about the history and contents of your source code. Written in TypeScript, can use Docker Compose to run locally.
  mergestat-lite is a command-line version of the tool, which runs SQL queries against local git repositories. Written in Go.
  MergeStat was included in “SQL for querying Git repos” tools list in Git Rev News Edition #82.
- World of Code is an infrastructure for study of software supply chains, utilizing Tokyo Cabinet, custom binary storage, MongoDB, and Clickhouse to store data, and which provides shell API and (limited) Python API for querying data from 173 million Git repositories on their infrastructure. Described in an article on arXiv from 2020.
git-com by masukomi is an interactive CLI tool to help you create commit messages that are not only readable, but follow a standardized format. Described in this Mastodon thread. Written in Bash.
git-identity (in Go) and GitID (in TypeScript, uses Node.js) are both tools that provide a convenient command-line interface to manage and switch between multiple identities on a single user account.

Releases

Git 2.42.0, 2.42.0-rc2, 2.42.0-rc1, 2.42.0-rc0
Git for Windows 2.42.0(1), 2.42.0-rc2(1), 2.42.0-rc1(1), 2.42.0-rc0(1)
libgit2 1.7.1
Bitbucket Server 8.13
GitHub Enterprise 3.9.4, 3.8.9, 3.7.16, 3.6.18, 3.9.3, 3.8.8, 3.7.15, 3.6.17, 3.10.0
GitLab 16.3 16.2.4, 16.1.4, 16.2.3, 16.2.2, 16.1.3, and 16.0.8
GitKraken 9.7.1, 9.7.0, 9.6.1
GitHub Desktop 3.2.9, 3.2.8
git-credential-azure 0.2.2, 0.2.1, 0.2.0, 0.1.0
git-credential-oauth 0.10.0

Credits

Git Rev News Edition 101 (July 31st, 2023)

chriscool — Mon, 31 Jul 2023 11:06:51 +0000

Git Rev News: Edition 101 (July 31st, 2023)

Welcome to the 101st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of June 2023 and July 2023.

Discussions

General

[ANNOUNCE] Virtual Contributor’s Summit 2023

Taylor Blau from GitHub announced that GitHub will host a Virtual Contributor’s Summit this year. Previously he announced that there would be no Git Merge in-person event this year.

The announce of the Virtual Contributor’s Summit 2023 contained links for participants to register, to suggest topics and to vote on proposed topics.

Reviews

[RFC PATCH 0/8] Introduce Git Standard Library

Calvin Wan sent a 8 patch long RFC series to the mailing list to introduce a “Git Standard Library”. This new library was intended to be a base library for other Git libraries to build upon.

This followed previous effort from Calvin and Elijah Newren to cleanup headers and internal APIs like the strbuf API to manipulate character strings and the git-compat-util API to provide wrapper compatibility functions masking OS differences. It also followed previous discussions about turning parts of Git into libraries and the ongoing video conferences that are regularly hosted by Google about libifying Git.

Building Git already involves creating an internal library called libgit.a that contains a lot of common code used by many Git commands. The Git executable is then created by linking all the object files for the Git subcommands (like git log) and the git command itself against libgit.a and a few external dependencies. The goal with the new Git Standard Library, also called git-std-lib.a, and the Git libification effort is to have a number of small independent libraries (like object-store.a, and config.a) all using git-std-lib.a. These small independent libraries would also be linked together to form libgit.a, which would then be used to create the Git executable like today. The benefit would be that “if someone wanted their own custom build of Git with their own custom implementation of the object store, they would only have to swap out object-store.a rather than do a hard fork of Git”.

The new Git Standard Library is considered necessary for the libification effort, because there are numerous circular and ubiquitous dependencies that are very difficult to untangle and it probably wouldn’t be worth untangling them. As the libification effort doesn’t promise stability of interfaces though, it would still be possible to extract some small libraries from git-std-lib.a later if there is ever a need to be able to swap them out.

Calvin noted that a pitfall of this series was the introduction of #ifdef GIT_STD_LIB preprocessor instructions to stub out some code and hide some function headers. He asked for comments about how it would be possible to avoid those instructions which make the code harder to understand. He also mentioned that some of the compatibility code in compat/ still had dependencies outside git-std-lib.a, but that it just meant that “some minor compatibility work” might be needed in the future.

As to the testing of the new library, he said that “the temporary test file added by the series will be replaced with unit tests once a unit testing framework is decided upon”, pointing to the related discussion. That discussion is actually an RFC patch series that in its latest version only adds an asciidoc document explaining the plan to add a unit test framework to Git and containing a table comparing the possible unit test frameworks that Git could adopt.

Victoria Dye and then Jeff Hostetler replied to the first patch in Calvin’s series saying that they didn’t agree with the fact that the Trace2 code wouldn’t be in git-std-lib.a. They pointed out that it should be possible to use the Trace2 tracing functions everywhere in the Git code, even in low-level functions. Calvin replied that he would look into possible solutions like redrawing the boundaries of the library or stubbing out tracing in it to accommodate that need.

Phillip Wood commented on a few patches saying he liked the idea, but suggested that the library should also contain the code related to gettext and to some basic data structures (“hashmap.c” and “string-list.c”). He also suggested some improvements and a way to deal with the Trace2 issue.

Junio Hamano, the Git maintainer, was happy that one patch removed the dependency many files had on “config.c”. He wondered though if another patch that removed a wrapper function to remove a dependency did the right thing, as the function had a number of callers. Glen Choo then chimed in to suggest an alternative way to remove that dependency and both Calvin and Junio agreed that this would be a good way forward.

Glen separately reported that he had trouble building the series. Calvin clarified that the series was based on Git v2.41 and sent a link to the code.

Linus Arver also replied to Calvin’s series by asking a number of questions. He wondered if adding the standard library would make it harder or not to refactor code into separate libraries or to create separate programs that would use only some Git API, like for example the API in “trailer.c” that helps parse commit message trailers (e.g. “Signed-off-by: Author Name author@example.com). He asked for more information about the tradeoffs between accepting the circular dependencies and untangling them, and made a number of other suggestions.

It’s not clear yet if the libification effort and the idea of a Git Standard Library will bring a lot of changes to the code base soon, but that could be an interesting possibility.

Developer Spotlight: Martin Ågren

Who are you and what do you do?

I’m Martin Ågren. I live in Sweden, where I spend some of my spare time in the garden or tending to the bees to the best of my abilities. I also enjoy reading books and listening to music (not at the same time).
What would you name your most important contribution to Git?

The number of breathtaking features I’ve contributed is probably a one-digit number ending in a zero. That said, I think I’ve contributed a bit to the documentation by fixing some fairly ugly misrenderings, but also by aligning the way it’s formatted by the two tools we support, asciidoc and asciidoctor. I guess we’ll never know this for a fact, but there’s a chance that I’ve saved someone’s crontab by fixing a bug that would eat it. I’m very happy that I fixed that bug before it was ever included in a release.
What are you doing on the Git project these days, and why?

I’m mostly just tinkering. I very rarely feel like there’s something actually missing from Git. I’m mostly trying to contribute in order to show that gratitude and to help others, without occupying too much bandwidth.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Complete the hash function transition. brian m. carlson has done a tremendous job making sure there are these two parallel worlds, if you want. What’s missing now is making them interoperable. This is not necessarily the biggest problem in current Git, but it could be something that won’t be fixed by short-term, this-quarter, profit-maximizing actors, so if I could decree a team to work on that without having to worry about “return on investment” and such, I’d probably go for that.
If you could provide users of Git with one piece of advise, what would it be?

The one thought I would like to somehow convey to everyone using Git is to commit early, commit often. Whatever crap you have ever had in your working tree, there’s an object containing it. Use git reset --hard, git rebase, git cherry-pick, whatever floats your boat, you will be able to bring it back and polish it up into a Git history that looks like you knew what you were doing all along.

I think this is really the point about Git: it teaches you how to pretend to be a good programmer, and once you start thinking of shaping your work like that, you actually might turn into one. Not because “fake it till you make it”, that’s just bullshit, but because you actually spend time approaching problems the right way and start thinking about how you present your solution.

Your “solution” is then not just the state of the working tree (“look! it compiles and all the tests pass, so it must be good!”), but also how you got there, as a series of well-motivated incremental changes.
What is your favorite Git-related tool/library, outside of Git itself?

I’m a big fan of tig, especially tig blame. I simply never use git blame. If I’m allowed to count git/contrib as “outside of Git itself”, I’ll be more than happy to recommend git jump. It’s not especially sexy, but I probably use it every single day and I find it extremely helpful.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

I still sometimes think back to when I posted my first patch series to the list. Peff wrote “[…] I’m very impressed with the attention to detail for a first-time contributor.”, to which Junio replied “Yes.”. Of course, a part of even remembering that is vanity on my part, but I do think those two sentences are fairly representative of each of their communication styles. They also capture perfectly well the kind of review style that I wish a lot more projects used. You know, it is allowed to not just point out something that is wrong or could be better.
What is your toolbox for interacting with the mailing list and for development of Git?

For the list, it’s gmail.com, lore.kernel.org/git, git am, git format-patch, and git send-email. I keep thinking I should set up something more advanced, but for the limited volumes I’m handling, it’s fine. For development of Git [and other stuff], it’s Vim, git diff, git add -p, git commit --amend, git rebase -i, git range-diff, tig blame, git jump (grep, merge, diff) and … maybe that’s about it. Well, git show and git log of course. Please note the -p in git add -p. I would like to live in a world where no-one blindly does git add . && git commit.
What is your advice for people who want to start Git development? Where and how should they start?

Do something you enjoy doing. Of all the people born any given year, not even one of them, on average, will ever become president of the United States. Don’t do open source because it could land you a nice job somewhere, sometime. Don’t do Git development because it seems like a good investment. Do open source because you believe in it and see some random thing that you want to contribute to. If you don’t see that, plant a flower instead and watch it grow.

This obviously comes from someone who is privileged enough to be able to say “don’t worry, be happy” and talk in metaphors about gardening. That said, I do think there’s a difference in keeping bees and tending to them. You shouldn’t want to keep them, you should want to help them do their thing. And if you want to help Git do its thing, great!

Start by lurking on the mailing list to get a feel for how it works. Then do some small improvement, and avoid growing the scope too much. Sleep on your patch, review it yourself and iterate that process a few times before actually sending it off.

Other News

Various

A Git community has been created in the programming.dev Lemmy instance.
Passwordless authentication is now available on GitHub.com (with passkeys), as a public beta.
Meet Smart Locks, a new way to reduce merge conflicts with Unity Version Control (previously Plastic SCM).
- Locks in DVCS were also supported in SourceGear’s Veracity SCM (which is no longer developed, it’s last version was from 2013).
- See also Git for games: current problems and solutions video from Git Merge 2019.

Light reading

Scaling merge-ort across GitHub by Matt Cooper on GitHub Blog, describing how and why GitHub have switched from performing merges and rebases using libgit2 to using merge-ort for it (available in Git since 2.33), and performing worktree-less rebases using the new work-in-progress git replay command. Merge commits were created using the merge-ort strategy on GitHub since September 2022, as mentioned in Git Rev News Edition #91.
Git and Jupyter Notebooks: The Ultimate Guide by ReviewNB. The article mentions the following tools:
- nbdime, mentioned first in Git Rev News Edition #37,
- jupyterlab-git extension, described in more detail in How to use the JupyterLab Git extension on ReviewNB Blog,
- ReviewNB app for GitHub, for when rich notebook diffs on GitHub fail,
- nbdev, which includes support for better Git handling for Jupyter notebooks (see Fix merge conflicts in jupyter notebooks for nbdev1, and Git-Friendly Jupyter for nbdev2), and was mentioned in Git Rev News Edition #69, and also mentioned in Edition #100 as one of alternatives for databooks tool,
- NBviewer and Binder services.
How To Automate Your Server Database Backup Using Git and cron, by Confidence Okoghenun on his blog (also on DEV.to).
How to Use Git Shallow Clone for Faster Repository Cloning (and cloning only a single branch, and creating sparse blobless and treeless clones) by Anthony Heddings on How-To Geek. This can be useful when you want to examine Git repos with long histories, and is also useful for Continuous Integration pipelines (CI/CD), since the CI/CD process likely does not need to know the entire Git history.
How To Undo or Reverse a Git Merge by Anthony Heddings on How-To Geek.
The Git Rebase Handbook – A Definitive Guide to Rebasing by Omer Rosenbaum on freeCodeCamp, continuing from Git Merge – The Definitive Guide mentioned in Git Rev News Edition #99 (and other posts).
Mastering Git Shortcuts: A Guide to Git Aliases by Pradumna Saraf on DEV.to - though the guide is limited to simple aliases, and does not cover forcing an alias to be treated as a shell command, or tricks that one can use for advanced handling of alias parameters.
.gitattributes Best Practices by Muhammad Rehan Saeed on his blog (2020).
The Power of Git: A Guide to Collaborative Version Control by BekahHW for OpenSauced on DEV.to.
A Guide to Perfecting Pull Requests by Kara Luton on DEV.to.
Effective Code Reviews by Addy Osmani on his blog.
The Gentle Art Of Patch Review by Sage Sharp on their blog (2014).

Easy listening

Git with Derrick Stolee on PodRocket (a web development podcast from LogRocket).

Git tools and sites

Emoji-Log — A simple Emoji Git commit log messages spec standard.
- Similar GitMoji standard — an emoji guide for your commit messages, was mentioned in Git Rev News Edition #47.
thefuck is a command line application which corrects your previous console command. Among others it includes series of rules for correcting mistakes when using Git (like typos in command names, trying to git add an ignored file, etc.). Written in Python.
New Relic CodeStream is a free open-source extension for VS Code, Visual Studio, and JetBrains (with support for more IDEs on the way) for putting collaboration tools in the IDE: supporting pull requests, issue management, observability, and code discussion.
jupyterlab-git is a JupyterLab extension for version control using Git.
ReviewNB is a paid GitHub and Bitbucket app for rich diffs and commenting (including code review) for Jupyter Notebooks, free for open source (for public repositories) and academic use: see pricing. You can request self hosted installation (distributed as Docker image).
pwclient is the command-line client for the Patchwork web-based patch tracking tool. Patchwork was mentioned in Git Rev News Edition #20, in passing in Edition #48 (as then base for snowpatch CI for patches, now also supporting GitHub Actions), in passing in Edition #55 (as being similar to patchew patch tracking and testing system), and in passing in Edition #88 (as being used by Sourceware service). Patchwork is used for some Linux kernel development.
JetBrains Academy offers a ‘Master Git and GitHub in 5 Hours’ course on Hyperskill for free, with the project-based part of the course available only for paid users (Premium).

Releases

Git for Windows 2.41.0(3), 2.41.0(2)
libgit2 1.7.0
GitLab 15.11.13 16.2.1, 16.2, 15.11.12, 16.1.2, 16.0.7, and 15.11.11, 16.1.1, 16.0.6, and 15.11.10
Bitbucket Server 8.12
Gerrit Code Review 3.6.6, 3.7.4, 3.8.1
GitHub Enterprise 3.9.1, 3.8.6, 3.7.13, 3.6.16, 3.9.0
GitKraken 9.6.0
GitHub Desktop 3.2.7
Tower for Mac 10.1
git-credential-oauth 0.9.1, 0.9.0
gitolite v3.6.13

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Eren Canpolat, Bruno Brito, Kristoffer Haugsbakk, Junio Hamano and Štěpán Němec.

Git Rev News Edition 100 (June 30th, 2023)

chriscool — Fri, 30 Jun 2023 11:06:51 +0000

Git Rev News: Edition 100 (June 30th, 2023)

Welcome to the 100th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of May 2023 and June 2023.

Some statistics about the ongoing first Git Rev News Readers Survey

The Git Rev News Reader Survey was announced in the previous edition with the goal to gather responses from the community to help improve Git Rev News. Unfortunately, there we got only 11 responses to the survey (among 250 visits). Compare this number to 3236 to 11498 responses to various Git User’s Surveys…

The results cannot be considered statistically significant, but here is what we have gathered so far:

Most enjoyed Git Rev News section was “Developer Spotlight (aka Interview)”, followed closely by “Discussions (General, Reviews, Support)”. Least enjoyed was the “Releases” section.
The order of Git Rev News section(s) agrees with readers expectations, with the exception of the “Releases” section thought to better be near the end, and the “Other News (aka Links)” to better be in the middle, swapping the order of those two sections.
The survey gathered various interesting suggestions, among others:
- more developer (or even user) interviews,
- include a brief description of what is in the link,
- interviews with some authors of Git tools,
- include short articles about how to do source control and how Git is being used,
- add an editorial piece to start off the newsletter,
- add an index of previous Git Rev News (e.g. ‘whom we interviewed’).
For the “Discussion” section the suggestions include adding headlines or subheadings, having some images (e.g. diagrams or screenshots) where appropriate, and adding a tl;dr summary to longer articles (or shortening them).
There was the idea of providing a simple web form to suggest contributors to be interviewed.
VonC was suggested for an interview, and Jeff King (aka peff) and Junio C. Hamano for re-interviews.

There will be further analysis of the responses in the future. Thank you very much to everyone who participated in the Reader Survey.

Discussions

General

Git participates in GSoC (Google Summer of Code) 2023

The following two contributors have been officially accepted to work on Git as part of the GSoC 2023:
- Kousik Sanagavarapu will work on the “Unify ref-filter formats with other pretty formats” project. Kousik will be co-mentored by Hariom Verma and Christian Couder. Some details about his work on the project could be found in his blog.
- Shuqi Liang will work on the “More Sparse Index Integrations” project. Shuqi will be mentored by Victoria Dye. Further details about the project and updates on progress can be found on Shuqi’s blog.
Congratulations to the accepted contributors!

Thanks also to the other contributors who applied and worked on micro-projects, but couldn’t be selected! We hope to continue to see you in the community!

Reviews

[PATCH 0/6] strbuf cleanups

Calvin Wan sent a 6 patch long series to clean up strbuf related code. strbuf is a basic structure along with related functions, implemented mostly in the “strbuf.c” and “strbuf.h” files, that is used to manipulate character strings.

The issue was that over time some functions with dependencies to other code had been added into those files, and Calvin’s series wanted to get rid of these dependencies “with the goal of eventually being able to stand up strbuf as a library”.

Most of the patches moved some functions to other files that were using them, and one of them removed the use of environment variables.

Junio Hamano, the Git maintainer, suggested that some functions that were moved to other files should be renamed so that they don’t start with “strbuf_” anymore, as they were not really string manipulating functions.

The series was also reviewed by Jeff King, Elijah Newren and Felipe Contreras, who overall liked it. They commented on some patches mostly to add some historical context or to ask for some clarifications.

Calvin sent a version 2 of the series that added a new patch at the beginning of the series to clarify the purpose of the strbuf functions at the top of “strbuf.h”. The other changes in this version were small clarifications in the commit messages of some patches or in code comments.

Junio commented on the last patch of the series though. This patch was supposed to remove the use of environment variables according to its subject, but was in fact removing the dependencies of strbuf functions on the comment_line_char global variable and adding a new parameter to those functions instead.

Calvin sent a new version of this patch calling it a v3 even though the other patches in the series were not resent. Elijah reviewed this v2/v3 patch series and suggested some minor changes in some commit messages.

Calvin then sent a version 4 of the series with the commit message changes suggested by Elijah and Junio.

Both Eric Sunshine and Phillip Wood chimed in to comment on this version. Eric suggested moving the comment added by the first patch of the series further up in “strbuf.h” and making it clear that this comment is for developers instead of mere users of the strbuf functions. Phillip suggested simplifying the parameters of a function where a new parameter was added by the last patch of the series.

Calvin then sent a version 5 of the series which included the suggestions made by Eric and Phillip. Eric replied with some further small comments about the first and last patches of the series.

Calvin then sent a version 6 of the series with Eric’s suggestions, and a few weeks later a version 7 of the series to fix a few minor issues related to the release of Git v2.41.0 in the meantime. It looks like this series will be merged to the ‘master’ branch soon though.

Developer Spotlight: John Cai

Who are you and what do you do?

My name is John Cai, and I started to contribute to the project back in 2021. I also lead the Git team at GitLab, where we aim to improve Git and add features that will make the lives of GitLab users and Git users better.
What would you name your most important contribution to Git?

Adding a --batch-command mode to cat-file was the first feature that I contributed to Git. It allows a single long running process to handle different cat-file queries. Most developers wouldn’t take advantage of this, but for Git servers it’s a nice feature.
What are you doing on the Git project these days, and why?

Things like documentation improvements, as well as working on some small features that will optimize the server side of things. At GitLab we are currently developing a system that will contain many ephemeral refs, so we recently added options to git-pack-refs(1) that allow the caller to specify refs to exclude from the packed refs file.

I still consider myself a bit of a newbie, but I love contributing however I can since Git is such an impactful project. Further, since our team interfaces with Git so much, I often notice opportunities for incremental improvements. Other times, we have explicit needs to add a feature or enhancement to support improvements to our Git data access layer in GitLab.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Transition the project to a new refs backend! There have been plenty of great discussions around this – whether to go with the reftables backend or a new format of the packed-refs file. Swapping out the refs backend would be a huge undertaking, but well worth it, in my opinion.
What is your favorite Git-related tool/library, outside of Git itself?

When reviewing code, I’ve been using meld. I overall like the UI.
What is your toolbox for interacting with the mailing list and for development of Git?

I use GitGitGadget mostly, but also b4 is great for trying out patches locally.
What is your advice for people who want to start Git development? Where and how should they start?

It can definitely be intimidating since the codebase is so storied and technically deep. My suggestion is to just dive in and get started with something small – whether that be a documentation improvement or a code cleanup marked with TODO. Also, keep an eye out for bug reports on the mailing list. Fixing bugs also gives you experience with different parts of the code base.

Part of my intimidation is not knowing how people on the mailing list would respond to my contributions. Experiencing how helpful people were, and the overall warmth of the community removed a lot of the emotional barrier of contributing.

Also, it’s easy to read into tone in text-only communication, but the mailing list is full of people who genuinely want to help. Don’t let the fear prevent you from contributing! You’ll learn incrementally each time you send something to the list.
If there’s one tip you would like to share with other Git developers, what would it be?

Spend more time than you think you need to on crafting commit messages. It goes a long way to clearly state the need, and how the patch addresses the need.

Also, look for existing APIs in the codebase 😄.

Other News

Various

Highlights from Git 2.41 by Taylor Blau on GitHub Blog.
Git 2.41 release - Here are five of our contributions in detail by John Cai on GitLab Blog.
The DVC 3.0 Stack: Beyond the Command Line by Dave Berenbaum on Iterative.ai blog. DVC (Data Version Control) was first mentioned in Git Rev News Edition #42.
Coming Up on Tower’s Roadmap (2023) by Bruno Brito on Tower’s blog.
Meet GitLab Duo, the suite of AI capabilities powering your workflows by David DeSanto on GitLab Blog.
Crafting a better, faster GitHub Code View by Joshua Brown on GitHub Blog.

Light reading

Setting Up SSH for Commit Signing by Bruno Brito on Tower’s blog.
Applying GitOps principles to your operations by Chris Reddington on GitHub blog. GitOps set of practices was first mentioned in Git Rev News Edition #42; the previous edition (#99) includes many links about GitOps / GitDevOps.
3 great Git alternatives: Fossil, Mercurial, and Subversion by Serdar Yegulalp on InfoWorld.
- An article about Fossil did appear in Git Rev News Edition #11, but is nowadays unavailable except through the Internet Archive.
- In Git Rev News Edition #87 you can find referenced an article about Why SQLite Does Not Use Git but Fossil.
Too Much Git? Try Gitless by Bryan Cockfield on Hackaday. Gitless was first mentioned in Git Rev News Edition #20.
How to Clean Up Your Local Repository with Git Commands by Emanuele Bartolesi for This is Learning on DEV.to.
Git Change Commit Message – How to Edit Commit Messages with Git Amend by Shittu Olumide on freeCodeCamp.
Git: rebase VS merge (simple) by Kristiyan Velkov on DEV.to is a second part of his series of articles about Git.
The Ultimate Guide to Writing Effective Commit Messages: Best Practices and Conventional Commits by Autumn Skerritt on her blog.
How to use Meld as a difftool for Git? by abbazs on DEV.to.

Easy watching

2023-06-20 GitLab Gitaly Community Office Hours on GitLab Unfiltered channel on YouTube, showing a live coding session developing a small feature in Git (the video is around 1 hour long, and included subtitles in English).

Git tools and sites

git-sweep is a command-line tool that helps you clean up Git branches that have been merged into master. Written in Python.
databooks is a package and a CLI tool to ease the collaboration between data scientists using Jupyter notebooks, by reducing the number of git conflicts between different notebooks and resolution of git conflicts when encountered.
- Alternatives include nbdev tool that creates programming environment out of Jupyter notebooks (first mentioned in Git Rev News Edition #69), nbdime tool for diffing Jupyter notebooks (first mentioned in edition #37), and jupytext tool for bi-directionally converting Jupyter notebooks to plain text files as either Markdown files or Python scripts (also mentioned in edition #69).
Awesome git addons is a curated list of add-ons that extend/enhance the git CLI, though a bit out of date (last change is from October 2021).

Releases

Git 2.41.0
Git for Windows 2.41.0(1)
GitHub Enterprise 3.8.5, 3.7.12, 3.6.15, 3.5.19, 3.9.0, 3.8.4, 3.7.11, 3.6.14, 3.5.18
GitLab 16.1 16.0.5, 15.11.9, 16.0.4, 16.0.3, 15.11.8, 16.0.2
Bitbucket Server 8.11
GitKraken 9.5.1, 9.5.0
GitHub Desktop 3.2.6, 3.2.5, 3.2.4
Tower for Windows 5.0 (blog post)
Tower for Mac 10.0 (blog post)
git-credential-oauth 0.8.0

Credits

Git Rev News Edition 99 (May 31st, 2023)

chriscool — Wed, 31 May 2023 11:06:51 +0000

Git Rev News: Edition 99 (May 31st, 2023)

Welcome to the 99th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of April 2023 and May 2023.

To help us improve Git Rev News, please participate in our first Reader Survey. It’s up only until our next edition, so for about one month.

Discussions

Support

Weird behavior of git log --before or git log --date-order

Thomas Bock reported an issue in a LibreOffice repository where some commits from around 2010 were treated by git log as if they had been created before 1980.

Commands like git log --before="1980-01-01" or git log --date-order both show or list some commits with an author date and a commit date from around 2010 as if they were from before 1980.

Thomas looked at the timestamps of the author and committer dates in these commits, but they didn’t appear to be broken, so he suspected a Git bug.

Peff, alias Jeff King, thanked Thomas “for providing a clear example and reproduction recipe” and pointed out that the commits that appeared to be from before 1980 were “malformed, but only slightly”. It appeared that their “author” and “committer” headers contained something like:

Firstname Lastname<firstname.lastname <Firstname Lastname<firstname.lastname@example.com>> 1297247749 +0100

instead of simply:

Firstname Lastname <firstname.lastname@example.com> 1297247749 +0100

that is, with an extra weird set of angle brackets.

Peff also found that there were two different code paths for commit parsing and they behaved differently when there was an extra set of angle brackets. One, which was used to fill in the fields of a struct commit, only parsed the “parents”, “tree”, and “committer timestamp” fields. For that last field, it was using the parse_commit_date() function which stopped at the first ‘>’ and then tried to parse the rest of the line as a timestamp, which failed and returned a 0 timestamp if there was a second ‘>’.

The other code path, used when the commit was displayed, called the split_ident_line() function to parse the “author” and “committer” headers, but this function was trying to find the last ‘>’ in these headers instead of the first one, which yielded the correct timestamp when there were two or more ‘>’.

Peff then suggested a patch to make parse_commit_date() behave like split_ident_line() and find the last ‘>’ instead of the first one. He also discussed other possible ways to fix the issue, including doing nothing as the commits were indeed malformed.

Kristoffer Haugsbakk replied to Peff saying he was using a tool called git repair to try to fix the original repo. But Peff said he wasn’t sure git repair would be able to fix it. He mentioned that git filter-repo or other tools would be able to fix it, but would require the commit history to be rewritten, which might not be “worth it for a minor problem like this”.

Kristoffer replied that he gave up with git repair as it didn’t seem to finish, but was actually more interested in seeing if the weird git log behavior went away to convince others it wasn’t a bug, rather than fixing the repo.

Peff suggested carrying on with git-filter-repo’s --commit-callback option, or alternatively piping git fast-export through sed, and then back to git fast-import, as he was almost certain git log would properly work if the repo was fixed.

A few weeks later Kristoffer sent the URL of a repaired repo. He said he couldn’t use git filter-repo, but “git commit-tree + git replace + git filter-repo --force worked”.

In the meantime, Junio Hamano, the Git maintainer, replied to Peff’s initial findings wondering which commit parsing function was used to populate the commit-graph files where commit data is cached, as it wouldn’t be good to record broken timestamps there.

Peff replied to Junio saying the commit-graph files are written from the parsed “struct commit” objects which is good as we want those cache files to always match the code that is used when they are not available. If Peff’s patch was applied to fix the parsing though, that would mean that existing commit-graph files would need to be manually removed, so that the fixed parsing could be used instead of broken values stored in those files.

Peff also discussed modifying the commit-graph code so that when a 0 timestamp was recorded for a commit, this commit would be parsed again, but thought it might not be worth the effort. Derrick Stolee discussed this idea too, but agreed with Peff saying “this seems like quite a big hammer for a small case”.

Thomas then thanked everyone for “clarifying this mystery” as the explanations given “already helped a lot”. He said that it would be very useful to fix the parsing of the broken commits, but, if that was considered to be too small a problem, he would like some kind of error handling to be introduced for commits with 0 timestamps instead of them being listed in the wrong time period.

Peff then sent a first version of a small patch series to properly fix the parsing of the broken commits and to fix another parsing bug he found in the same parse_commit_date() function.

Junio reviewed Peff’s patches and made a few suggestions, mostly about code comments. Peff took them into account and sent a version 2 of his patch series which behaved in the same way as the previous one, but had improved code comments.

Phillip Wood then wondered if it would be better to not use strtoumax(3) to parse timestamps as this standard C library function is using the standard isspace(3) while we are using our own version of isspace(3) which is different. Possible issues with strtoumax(3) could also be related to different characters being considered digits than in our code. This kind of issues come from the fact that strtoumax(3), like many other standard C library functions, is taking the current locale into account.

After some discussions between Peff, Phillip and Junio, Peff sent a version 3 of his patch series with small changes. Especially the new version makes sure Git rejects timestamps that start with a character that we don’t consider a whitespace or a digit or the ‘-‘ character before using strtoumax(3) as this was considered enough to avoid issues related to this function.

Phillip, Junio and Peff discussed this version a little bit more but found it good, so it was merged and these changes will be in Git v2.41.0 which will be released soon.

Releases

Git 2.41.0-rc2, 2.41.0-rc1, 2.41.0-rc0
Git for Windows 2.41.0-rc2(1), 2.41.0-rc1(1), 2.41.0-rc0(1)
Bitbucket Server 8.10
Gerrit Code Review 3.5.6, 3.6.5, 3.7.3, 3.8.0
GitHub Enterprise 3.8.3, 3.7.10, 3.6.13, 3.5.17
GitLab 15.11.6 16.0.1, 16.0, 15.11.5, 15.11.4, 15.11.3, 15.10.7, and 15.9.8, 15.11.2, 15.10.6, and 15.9.7, 15.11.1, 15.10.5, and 15.9.6
GitKraken 9.4.0
GitHub Desktop 3.2.3
Sourcetree 4.2.3
Tower for Mac 9.3, 9.4 (9.4 blog post)
git-credential-oauth 0.7.0

Other News

Various

GitHub code search is generally available by Colin Merkel on GitHub Blog.
- See also A brief history of code search at GitHub in Git Rev News Edition #82, and The technology behind GitHub’s new code search in edition #96.
- GitHub’s New Code Search is Bad for Finding Code by Alex Ivanovs on Stackdiary (complaining about lack of sort by new).

Light reading

Modeling Git Internals in Alloy, Part 3: Operations on Blobs and Trees by Brian Hicks on bytes.zone continues the series of articles from previous edition.
Why I prefer trunk-based development by Trisha Gee.
- This article references Perceived Barriers to Trunk Based Development by Dave Farley on his weblog (2018).
- You can find more about this workflow on Trunk Based Development site, first mentioned in Git Rev News Edition #24.
- Martin Fowler describes advantages and disadvantages of trunk-based development versus feature branches in Patterns for Managing Source Code Branches (biased towards better support for Continuous Integration), mentioned first in Git Rev News Edition #63.
- For the other side of this discussion, see for example Working with Feature Branches by Bruno Brito on Tower’s blog, mentioned in Git Rev News Edition #88.
5 Version-Control Systems that Game Developers Should Know About by Sharone Zitzman on The New Stack. Those 5 VCSs are: Git, Perforce, Plastic SCM (now Unity Version Control), SVN, and Diversion (cloud SCM, in beta).
9 best GitHub [Android App] alternatives in 2023 by Charnita Fance on Android Police.
Git Merge – The Definitive Guide by Omer Rosenbaum on freeCodeCamp.
Undo a [published] commit in Git by Angelos Chalaris on 30 Seconds of Code.
Git Best Practices – A Guide to Version Control for Beginners by Adekola Olawale on freeCodeCamp.
Common Git Issues and How to Troubleshoot Them by Abdelrahman Mohamed Allam on DEV.to, part of the Mastering Git: Essential and Advanced Commands for Developers series.
The Power of Pre-Commit for Python Developers: Tips and Best Practices by Deep Singh on DEV.to.
- Pre-Commit framework for managing and maintaining multiple multi-language pre-commit hooks (written as Python module) was first mentioned in Git Rev News Edition #45.
Creating effective pull requests, by madhadron (Frederick J. Ross).
How to Make your [Python] Code Shine with GitLab CI Pipelines by fernanda rodríguez on Medium.
CI/CD with KiCad and GitLab by Stefan Schüller on his blog (on GitHub Pages).
Code review at the speed of email by Drew DeVault on Drew DeVault’s blog (2022).
- See also for example The advantages of an email-driven git workflow by Drew DeVault, mentioned in Git Rev News Edition #41.
Connect to multiple Git accounts of the same vendor (GitHub, Gitlab) portal by Rahul Mahadik on DEV.to, originally guest-published at theonetechnologies.com.
Database branching: three-way merge for schema changes: Learn how PlanetScale uses Git-like three-way diff to resolve schema change conflicts across database branches. Article by Shlomi Noach on PlanetScale Blog.
- You can find few tools to help version-control database schemas in Git Rev News Edition #60; you can also find there another article by Shlomi Noach.
- In Git Rev News Edition #82 you can find articles about different ways version control and databases connect, and tools that can version control database schema (perform database migrations), or version control queries, or version data within schema, etc.
Version Control Your ML (Machine Learning) Model Deployment With Git using Modelbit by Avi Chawla, published in Towards Data Science, a Medium blog.
GitOps - Operations by Pull Request (2017) and What Is GitOps (2018) by Alex on Weaveworks blog.
- Another article from Weaveworks about GitOps can be found in Git Rev News Edition #42 (2018).
- You can find more about GitOps / GitDevOps on GitOps.tech and OpenGitOps sites, first mentioned in Git Rev News Edition #62 and #94, respectively.
4 Core Principles of GitOps by Alex Williams, and GitOps as an Evolution of Kubernetes by Steven J. Vaughan-Nichols on The New Stack.
Reproducible Data Dependencies for Python [with Quilt], a guest post by Aneesh Karve published in Jupyter Blog (Medium-based blog).
- DagsHub, a web platform for storing, versioning and managing data (data hub), similar to Quilt Data mentioned in this blog post, was mentioned in various articles linked to in Git Rev News Edition #72, #85, #96, and tangentially in #97.
- See also links about data versioning in Git Rev News Edition #96.
GitHub Copilot X CLI is your new GIT assistant by Leonardo Montini for This is Learning, a part 3 in GitHub Copilot X (5 Part Series) on DEV.to. Originally published at leonardomontini.dev.
- Similar article, GitHub Copilot for CLI makes Terminal scripting and Git as easy as asking a question can be found in Git Rev News Edition #98.

BranchGPT: The AI-Powered Solution to Branch Names by Sebastian Tiedtke on Stateful.com blog (Tongue-in-cheek over the top take on AI).

Easy watching and listening

For those who just don’t Git it (The Stack Overflow Podcast | Ep. 573) where Pierre-Étienne Meunier, creator and lead developer of open-source version control system Pijul (mentioned in Git Rev News Edition #9, #24 and #38), talks about version control, functional programming, and OCaml.

Git tools and sites

Bytebase - database schema change and version control (the GitLab for Database DevOps): web-based collaboration workspace to help DBAs and developers manage the database development lifecycle.
Quilt Data is a self-organizing data hub, consisting of a Python API, web catalog, and backend to manage data sets in AWS S3. The backend service is based on open-source Quilt Python package (documentation. The development of jupyterlab-quilt extension seems to be stalled, though.
GitOps Principles v0.1.0 published by OpenGitOps.
GIT Web Terminal (Git in your browser) was created using isomorphic-git (a pure JavaScript implementation of git for node and browsers). Source code on GitHub: jcubic/git.
- isomorphic-git was first mentioned in Git Rev News Edition #40.
schemadiff is a declarative, programmatic library in Vitess that can produce a diff in SQL format of two entities: tables, views, or full blown database schemas.
- Compare sqldiff.exe, which is a command-line utility program (Windows binary) that displays content differences between two SQLite databases. Mentioned in Git Rev News Edition #87.

Credits

Git Rev News Edition 98 (April 30th, 2023)

chriscool — Sun, 30 Apr 2023 11:06:51 +0000

Git Rev News: Edition 98 (April 30th, 2023)

Welcome to the 98th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of March 2023 and April 2023.

Discussions

Support

Suspected git grep regression in git 2.40.0

Stephane Odul reported that running the command

git grep -cP '^\w+ = json.load'

on some files of a private repo started failing consistently with an exit code of -11 in Git v2.40.0 while it worked with previous Git versions.

Bagas Sanjaya replied to Stephane asking him if he could use git bisect between v2.39.0 and v2.40.0 to see which commit in Git’s history broke the feature.

Junio Hamano, the Git maintainer, thought the issue might have been created by a recent change in how Git uses the PCRE2 library. This change made Git try to run PCRE2’s JIT (Just In Time) compiler on a sample pattern and fall back to not using the JIT compiler if the attempt failed.

Junio said it could alternatively be that the version of the PCRE2 library linked to v2.40 had been updated compared to the one in previous Git versions, but asked if it made a difference to disable the JIT compiler by prefixing the pattern with (*NO_JIT).

Mathias Krause, who had worked on PCRE2 related issues recently, replied that another commit with the subject “grep: correctly identify utf-8 characters with {b,w} in -P” seemed more suspect to him as it was about both the -P option and the \w pattern.

Looking at the diff of that commit, Mathias found that it added the PCRE2_UCP flag to the PCRE2 library call when an UTF-8 locale was used, and that PCRE2 had a PCRE2_ERROR_UTF8_ERR9 (-11) error code described as “5th-byte’s two top bits are not 0x80” that matched the exit code of -11 which Stephane got.

Mathias then asked Stephane if a file in his repo might contain invalid UTF-8 output, and suggested testing this using the following command:
```
$ iconv -f UTF-8 your_file > /dev/null && echo OK || echo "Not valid"
```
Stephane replied that he created a custom pipeline to try to reproduce the issue and found that restricting the git grep command to Python files (using '*.py') was a good workaround, and that the issue was likely related to other files in “various formats, including potentially some binaries that would definitely not be proper UTF-8”. He also noted that using (*NO_JIT) as suggested by Junio prevented the issue but slowed down the command a lot for some patterns.

Mathias, in the meantime, was able to reproduce the error on the Git repo. He got a segfault and also a backtrace under gdb, but the backtrace was very short and without any debug symbols, so he supposed that it happened in the call stack of PCRE2’s JIT compiler. Looking at the memory mapping and the instructions also seemed to point to a JIT compiler bug.

Mathias then reverted the commit that added the PCRE2_UCP flag to the PCRE2 library call, and found that it fixed the bug, which confirmed his earlier suspicion about that commit.

Stephane thanked Mathias for his great work and left saying he was happy with the workaround he had found and did not believe there was much more he could contribute to the issue.

Mathias replied to his previous email saying he had found “an interesting entry in the PCRE2’s changelog for version 10.35”:
https://github.com/PCRE2Project/pcre2/blob/pcre2-10.35/ChangeLog#L66:
“17. Fix a crash which occurs when the character type of an invalid UTF character is decoded in JIT.”

He concluded that it was needed to implement “yet another quirk to handle these broken versions”, and came up with an in-email patch that was not using the PCRE2_UCP flag when Git was compiled to link to a PCRE2 version lower than 10.35. He wondered though if it was better to just revert the commit that had introduced the PCRE2_UCP flag.

Junio replied to Mathias by first thanking him for “all the investigation and a prompt fix” and then saying that the approach in his patch was more sensible than reverting the commit. He suggested a small code change though.

Mathias agreed with Junio’s suggestion and sent a version 2 of his patch that was then merged into the master branch.

Releases

Git 2.40.1 and friends
Git for Windows 2.40.1(1)
libgit2 1.6.4
GitLab 15.11 15.10.4, 15.7.9, 15.8.6, 15.10.3, 15.10.2, 15.10.1, 15.9.4, and 15.8.5
Bitbucket Server 8.9
Gitea 1.19.1
GitHub Enterprise 3.8.2, 3.5.16, 3.7.9, 3.6.12
GitKraken 9.3.0
GitHub Desktop 3.2.2, 3.2.1
git-credential-oauth 0.6.0

Other News

Various

Git security vulnerabilities announced: CVE-2023-25652 and CVE-2023-29007, and MS Windows specific CVE-2023-25815, CVE-2023-29011, and CVE-2023-29012. By Taylor Blau on GitHub Blog.

Light reading

Git and GitHub for Designers by Bruno Brito on Tower’s blog.
Git-Sim 3 Month Dev Update: Community Response, New Features, & The Future by Jacob Stopak on Initial Commit. Git-Sim was mentioned in Git Rev News Edition #95.
Smoother rebases with auto-squashing Git commits and Super-charging ‘git rebase’ with ‘git absorb’ by Andrew Lock on .NET Escapades. git-absorb (a port of Facebook’s hg absorb extension for Mercurial) was mentioned in passing in Git Rev News Edition #72.
Modeling Git Internals in Alloy, Part 1: Blobs and Trees and Modeling Git Internals in Alloy, Part 2: Commits and Tags by Brian Hicks on bytes.zone. Alloy is a tool (with its own domain-specific programming language) used for making and checking models of other software.
Avoiding the merge trap by Jonathan Corbet on LWN.net describes how one should explain merges in pull requests sent to Linus Torvalds.
Notes on graphics programming and version control Tyler Angert on tyler.cafe blog.
Introducing the Space Git Flow by Evgenia Verbina on JetBrains Blog. Space Git Flow is a branching strategy similar to Git Flow (first mentioned in Git Rev News Edition #5) and specifically GitHub Flow, used by JetBrains to develop their products including Space development platform / software forge.
See also:
- Please stop recommending Git Flow! by George Stocker, mentioned in Git Rev News #61.
- Patterns for Managing Source Code Branches by Martin Fowler, mentioned first in Git Rev News #63.
Convert git log output to JSON using jq with proper escaping, on Simon Willison’s TILs (Today I’ve Learned).
Quickly formatting a stack of commits by Waleed Khan on Steno & PL personal blog. It uses the git test command from the git-branchless suite of tools, which was first mentioned in Git Rev News Edition #76.
How to Install GitQlient on Your Synology NAS by Marius Bogdan Lixandru on his personal blog: Marius Hosting.
Some ~~secret~~ git tricks that come in handy by raghav yadav on DEV.to.
Git banned.h: Why Git’s Maintainers Have A List Of Banned Standard C Library Functions by Jacob Stopak on Initial Commit.
GitHub Copilot for CLI makes Terminal scripting and Git as easy as asking a question by Christian Heilmann on DEV.to.

sqlite-history: tracking changes to SQLite tables using triggers by Simon Willison on his Weblog.
SmartCommit: A Graph-Based Interactive Assistant for Activity-Oriented Commits [PDF] (DOI:10.1145/3468264.3468551) describes a graph-partitioning-based interactive tool to help split tangled changesets. The paper is accompanied by the code for the core algorithm of SmartCommit, a demo GUI client, and dataset and the visualization scripts used in the article. Since then, similar research studies have been conducted, like ComUnt and UTango, which cite the SmartCommit article.

Git tools and sites

List of Free Learning Resources (In Many Languages) by the Free Ebook Foundation, includes the list organized by subject, where there are free books about Version Control Systems, including Git. Some of those were mentioned in Git Rev News. This list was originally a clone of StackOverflow - List of Freely Available Programming Books. Has a dynamic webpage for searching the list at https://ebookfoundation.github.io/free-programming-books-search/.
GitQlient is a multi-platform Git client written with Qt, originally forked from QGit.
Gut is a user-friendly Git CLI for Windows, Mac, and GNU/Linux. Written in Go, still in alpha stage of development.
srcsnap (repository) is a screenshot-driven version tracking tool, written using Electron. It’s described in Srcsnap — Screenshot-Driven Version Tracking post on Future Sketches MIT Media Lab group blog.
diff2html is a JavaScript library that generates pretty HTML diffs from git diff or unified diff output.

Credits

Git Rev News Edition 97 (March 31st, 2023)

chriscool — Fri, 31 Mar 2023 11:06:51 +0000

Git Rev News: Edition 97 (March 31st, 2023)

Welcome to the 97th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of February 2023 and March 2023.

Discussions

Support

Bug report: symbolic-ref –short command echos the wrong text while use Chinese language

Mengzi Yi (孟子易) sent a bug report to the mailing list saying that when a Chinese name like 测试-加-增加-加-增加 was given to a branch, then calling git symbolic-ref --short HEAD on that branch didn’t result in the right output (for example 测试-� instead of maybe 测试-加).

Peff, alias Jeff King, replied saying that he couldn’t reproduce the issue on Linux and wondered if it was related to using MacOS as its HFS+ filesystem might do some Unicode normalization. He said that it might alternatively be related to the shortening code in shorten_unambiguous_ref() treating the names as bytes instead of characters. Another possibility he mentioned was that the shortening code, which used scanf(), was assuming that the resulting string could not be longer than the input, but that this might be wrong when some Unicode normalization and locale were used.

Eric Sunshine replied to Peff saying he was able to reproduce the bug on MacOS 10.13 (while Mengzi used MacOS 13.2), but that it didn’t appear to be related to HFS+ Unicode normalization as on disk the bytes of the branch name he got were the same as what Peff got on Linux.

Peff replied to Eric asking if he could test a patch that would add debug output and allocate twice as much memory for the shortened name that would store the output from scanf() than for the input of that function. Peff said the debug output on his Linux machine showed that the input was 39 bytes long while the output was 28.

Eric tested Peff’s patch and initially reported 39 and 9 for the input and output respectively. When setting LANG=zh-CN.UTF-8, he got the same input and output lengths as Peff though, which pointed to scanf() being indeed the culprit.

Junio Hamano, the Git maintainer, replied to Eric’s findings saying “Well, that’s … criminal.” and wondering if setting LANG to $ANY_VALID_ONE.UTF-8 would work the same way.

This made Eric realize that the zh-CN language code he used was invalid (it should have been zh_CN, so with an underscore character instead of a dash). Eric anyway found out that using valid LANG codes like en_US, fr_FR, de_DE, ru_RU and zh_CN resulted in the 测试-? truncated output, while using LANG=C yielded the correct 测试-加-增加-加-增加 output.

Junio, Peff and Eric discussed these results further, wondering what scanf() on MacOS could be doing wrong. Then Peff suggested replacing the call to this function with some manual parsing, and sent a sample in-email patch to do that.

Eric tested Peff’s patch and reported that it looked correct, worked nicely and fixed the issue. He also agreed with the approach of getting rid of scanf() calls in general.

Peff then sent a regular small patch series based on his previous patch, which fixed a leak and made the changes easier to follow.

Junio and Eric reviewed the series and then discussed with Peff a bug Junio found in it. Then Peff sent a version 2 of the patch series that fixed the bug and added tests.

Torsten Bögershausen in the meantime tried to reproduce the original bug and discussed how to do that with Eric. He also commented on the new tests in the version 2 of the patch series as he found that it wasn’t clear in which context the bug could appear. Junio suggested some clarifications that were approved by others. The resulting patches were merged and included in the recent Git v2.40.0 release.

Releases

Git 2.40.0, 2.40.0-rc2, 2.40.0-rc1
Git for Windows 2.40.0(1), 2.40.0-rc2(1), 2.40.0-rc1(1), 2.40.0-rc0(1)
libgit2 1.6.3, 1.6.2
GitHub Enterprise 3.8.1, 3.7.8, 3.6.11, 3.5.15, 3.4.18, 3.8.0, 3.7.7, 3.6.10, 3.5.14, 3.4.17
GitLab 15.10 15.9.3, 15.9.2, 15.8.4, and 15.7.8
Gitea 1.19.0
Gerrit Code Review 3.7.2
GitKraken 9.2.1, 9.2.0
GitHub Desktop 3.2.0
Sourcetree 4.2.2
Tower for Windows 4.3

Other News

Various

Highlights from Git 2.40 by Taylor Blau on GitHub Blog.
public-inbox.org/git to be downgraded to a cheaper VPS.
- There is https://lore.kernel.org/git/ if there are problems with the public-inbox.org instance.
Unleash your potential with GitHub Octernships: a path to a thriving tech career by Arkodyuti Saha on GitHub Blog.
Future-proofing Git repository maintenance by Patrick Steinhardt on GitLab blog.
Notes from a video conference on Thursday March 30 named libification eng discussion organized by Emily Shaffer are available.

Light reading

How to Improve Performance in Git: The Complete Guide by Bruno Brito on Tower’s blog.
Integrating 1Password SSH with Git (and Tower!) by Bruno Brito on Tower’s blog.
Slice, Dice, and Squash Your Git Commit History by Anthony Fung on Diary of a Web Developer Substack and on DEV.to as 3rd part of The Secret of Tidy Git Repositories Series.
Git fundamentals, a complete guide by Leandro Proença on DEV.to.
See also:
- Git from the Bottom Up by John Wiegley, mentioned in Git Rev News Edition #2,
- Git for Computer Scientists by Tommi Virtanen,
- and maybe also Think Like (a) Git: a guide for the perplexed by Sam Livingston-Gray.
Options to close pull requests on GitHub and Merge, squash & rebase on GitHub - pros & cons by Kacper Rychel on DEV.to.
How to Reset a File or Commit in Git by Ihechikara Vincent Abba on freeCodeCamp.
How atomic Git commits dramatically increased my productivity - and will increase yours too by Samuel Faure on DEV.to and on Such Dev Blog.
Working with Git in JetBrains’ Rider IDE by Andrew Lock on his .NET Escapades blog.
GitHub Desktop 3.2 adds pull request preview – but is a GUI needed for Git? by Tim Anderson on Dev Class.
Best 8 Data Version Control Tools for Machine Learning 2023 by Zoumana Keita on DagsHub Blog.
- See also links about data versioning in previous Git Rev News.
A better Git workflow? proposal by uje on the Julia Language Discourse forum.
Code Commit Guidelines using Conventional Commits by Pragnesh Ghoda on ProAndroidDev, a Medium blog.
- The Conventional Commits specification was first mentioned in Git Rev News Edition #52.

Empowering weak primitives: file truncation to code execution with Git by Thomas Chauchefoin on Sonar(Source) Blog (note that it is not about a vulnerability in Git).
References the Securing Developer Tools: Git Integrations blog post.
What the ML is up with DevSecOps and AI? by Taylor McCaslin on GitLab Blog.

Git tools and sites

There are a few tools that use GPT-3 / ChatGPT Large Language Model (LLM) to help write commit messages. Please read the proposed commit message before accepting it, especially for more complex changes. Those tools, as far as we understand it, do not take information from an issue tracker, or from code review comments attached to a pull request (or contained in a specialized tool such as Gerrit) – so they cannot add this information to the proposed commit message, they can only halucinate it.
All tools listed here require an API key from OpenAI.
- OpenCommit is a GPT CLI to auto-generate impressive commits in 1 second; it uses Conventional Commits, and can use GitMoji. Written as Node.js CLI app.
  - See also OpenCommit: GPT generates impressive commits in 1 second (open-source) by Dima Sukharev on DEV.to.
- AI Commits is a CLI app (aicommits) that writes your Git commit messages for you with AI, that can also be used as prepare-commit-msg hook. Written as Node.js v14+ CLI app.
  - See also AI generated Git commit messages by Brian Douglas on DEV.to.
- ai-commit is a command line tool that uses OpenAI’s language generation capabilities to generate conventional commit messages for your Git repositories. Written in Go.
- gptcommit is a Git prepare-commit-msg hook for authoring commit messages with OpenAI’s GPT-3 language model. Written in Rust.
  - Mentioned in Git Rev News Edition #95; see also an article about this tool there.
Planar is a Chrome extension that adds features used internally by big tech to speed up and simplify GitHub code review.
- See also Planar - Add 10x features to GitHub code review by Eshan Agarwal on Y Combinator (Launch YC).
Git for Computer Scientists by Tommi Virtanen is a quick introduction to Git internals for people who are not scared by words like directed acyclic graph.
Think Like (a) Git: a guide for the perplexed by Sam Livingston-Gray, intended for “advanced beginners” with Git to help them achieve some level of Git enlightenment.

Credits

Git Rev News Edition 96 (February 28th, 2023)

chriscool — Tue, 28 Feb 2023 11:06:51 +0000

Git Rev News: Edition 96 (February 28th, 2023)

Welcome to the 96th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of January and February 2023.

Discussions

Support

Bug?: ORIG_HEAD incorrect after reset during git-rebase -i

Erik Cervin Edin sent an email to the mailing list with steps to reproduce a behavior that he didn’t like. The steps consisted of an interactive rebase during which a commit was edited and a reset which was performed while editing the commit.

After editing, git rebase --continue finished the rebase. But then Erik expected ORIG_HEAD to point to the tip of the rebased branch before the rebase, while instead it pointed to the HEAD before the reset.

ORIG_HEAD is one of the pseudo-references that some Git commands use, like FETCH_HEAD, MERGE_HEAD, and a few others.

Phillip Wood replied to Erik saying that it was expected that git reset would change ORIG_HEAD to HEAD just before it was performed. He suggested using the reflog with something like branch-name@{1} where branch-name is the branch being rebased and the @{1} part indicates the previous entry in the reflog for the branch.

Erik replied that he knew about the reflog but just expected ORIG_HEAD to be reset to .git/rebase-merge/orig-head at the end of the rebase. .git/rebase-merge/orig-head is an internal file that stores the tip of the branch before a rebase operation.

Philippe Blain replied to Erik that he just hit the same bug. He also said that he was confused by the rebase documentation and supplied the series of commands he used to get hit.

Phillip Wood replied to both Erik and Philippe Blain that if we changed the behavior to make ORIG_HEAD point to the tip of the branch before it was rebased, some people might not be happy as they might expect git reset to have changed ORIG_HEAD. Other people might expect on the contrary that ORIG_HEAD was always set to the tip of the branch before the rebase when the rebase stopped, which would mean that git rebase --continue would always need to make sure ORIG_HEAD fulfilled that expectation.

Phillip said he thought the situation was confusing and he didn’t see a way to make it clearer.

Philippe Blain agreed that some people might rely on the current behavior and said he would send documentation updates to make things clearer.

He then sent a patch series consisting of small changes to the documentation of a number of commands: cherry-pick, merge, rebase and reset, as well as to the documentation about Git revisions.

Junio Hamano, the Git maintainer, commented on some wordings, which after short discussions led Philippe to send a version 2 of his series with very few changes.

This version was accepted and later merged into the master branch.

Releases

Git 2.40.0-rc0, 2.39.2 and friends
Git for Windows 2.39.2(1)
libgit2 1.6.1, 1.5.2
Bitbucket Server 8.8
Gerrit Code Review 3.5.5, 3.6.4, 3.7.1
GitHub Enterprise 3.7.6, 3.6.9, 3.5.13, 3.4.16, 3.8.0, 3.7.5, 3.6.8, 3.5.12, 3.4.15
GitLab 15.9.1 15.9, 15.8.2, 15.7.7 and 15.6.8, 15.8.3, 15.8.1
GitKraken 9.1.1, 9.1.0
GitHub Desktop 3.1.8, 3.1.7, 3.1.6
tig 2.5.8
Tower for Mac 9.2
Tower for Windows 4.2 (blog post)

Other News

Various

The Git project has been accepted as a Mentor Organization for Google Summer of Code (GSoC) 2023. We could still add project ideas to our idea page and volunteers to (co-)mentor are still welcome.
GitLab Improves Merge Requests, GitOps Functionality and More by Matt Saunders on InfoQ, about versions 15.3 through 15.8.
Git archive generation meets Hyrum’s law by Jonathan Corbet on LWN.net (affecting Git and GitHub).

Light reading

Will GitOps Change Software Development Forever? by Harshini on Analytics Insight.
Git signoff and signing like a champ by Josef Andersson on DEV.to.
How to Merge a Git Feature Branch with a Squash Commit by Luis Esteban Saravia M on DEV.to.
This is an alternative to repeatedly using the squash command of the interactive rebase.
Why I love GitLens in my VsCode - Part 1, Part 2, and Part 3 by Luca Del Puppo on his blog.
Also available on DEV.to.
Data versioning, a rough work-in-progress notebook by Dan MacKinlay. Includes descriptions of
- Data Version Control (DVC) (first mentioned in Git Rev News Edition #42),
- Dolt, which is a version controlled SQL database (first mentioned in Git Rev News Edition #62),
- Pachyderm (first mentioned in Git Rev News Edition #49),
- git-annex - not targeted specifically at data science (first mentioned in passing in Git Rev News #3),
- DataLad,
- Go Get Data (ggd) from the genomics community; it seems to be a lighter version of Pachyderm,
- Splitgraph, which works on top of PostgreSQL,
- Sno to store geospatial and tabular data in Git
  (see also Kart, mentioned in Git Rev News #85, which is not listed in this notebook).
The notebook also mentions Pangeo Forge (like Conda Forge, but for data), Intake (lightweight package for finding, investigating, loading and disseminating data), and Flat Data - formerly GitHub OCTO (to bring working sets of data to your repositories, based on the “Git scraping” approach pioneered by Simon Willison (mentioned in Git Rev News Edition #68)).
See also Git Rev News #82, which mentions tools for version controlling database schemas, version controlling queries, data versioning, etc. – all taken from articles on DoltHub Blog.
The Git source code audit, viewed as a Rust programmer by Litchi Pi (Tim); the audit itself was mentioned in Git Rev News #95.
An Easy git Workflow by Curtis “Ovid” Poe on DEV.to.
Also available as Easy Git Workflow (2020) on (Technical) Articles by Ovid.

The technology behind GitHub’s new code search by Timothy Clem in the Engineering section of the GitHub Blog.
Mobile Price Classification: An Open Source Data Science Project with Dagshub by Davis David (@davisdavid) on HackerNoon.
- The workflow described in this article uses DVC (first mentioned in Git Rev News Edition #42), DAGsHub (first mentioned in Git Rev News Edition #72), MLflow, and the Streamlit library.
FAIR data pipeline: provenance-driven data management for traceable scientific workflows; an open access research article in Volume 380, Issue 2233 of Philosophical Transactions of The Royal Society A (DOI:10.1098/rsta.2021.0300).

Easy watching

Move Commits Between Branches in Git by Leonardo Montini, also known as Dev Leonardo.
You can read the accompanying Move Commits Between Branches in Git - 3 Different Methods article on DEV.to (for This is Learning), 5th part of the git better - Improve your git skills series.

Git tools and sites

conventional: comments are a set of conventions to make code review comments to be easy to grok and grep.
- This can be considered a companion to Conventional Commits specification, first mentioned in Git Rev News Edition #52.
Flipt is an open source, self-hosted feature flag solution.
- Feature Flags or Feature Toggles are a technique that allows to modify system behavior without changing code. They are often used with Trunk Based Development, as described in Patterns for Managing Source Code Branches by Martin Fowler, which was mentioned in Git Rev News Edition #63.
git-workflow by Curtis “Ovid” Poe is a simplified subset of the Git tools used by All Around the World company for software development. It provides three new commands: git refresh, git pushback and git done.
Git-Heat-Map is a tool to visualize a Git repository by diff activity using a treemap chart.
Diff/merge tools and Git GUIs - notebooks of Dan MacKinlay.
Git tricks: Dan MacKinlay’s notes and links, not intended to be tutorial.
Awesome CLI Apps is a curated list of command line apps, including the ones for Version Control.
Automerge 2.0 is a CRDT, or “Conflict-free Replicated Data Type”, that one can use to implement real-time collaboration for an application, which is focused on optimizing editing of plaintext.

Credits

Git Rev News Edition 95 (January 31st, 2023)

chriscool — Tue, 31 Jan 2023 11:06:51 +0000

Git Rev News: Edition 95 (January 31st, 2023)

Welcome to the 95th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of December 2022 and January 2023.

Discussions

Support

Question: How to execute git-gc correctly on the Git server?

ZheNing Hu asked about how he could run git gc correctly on his own Git server. He seemed to be afraid by the git gc documentation saying that there is a risk of failures and repository corruption when the command is run concurrently with other Git processes.

He said that he read about git gc --cruft which could overcome these issues, but that he was still using Git v2.35 on his server while --cruft was introduced in v2.38.

He also wondered if there was a need for git gc to set a repository level lock blocking most or all other Git operations, and what these operations – especially git clone and git push – should do or report when hitting this lock.

Ævar Arnfjörð Bjarmason replied that running git gc on a “live” repo was always racy, but the odds of corrupting the repo were becoming very small when the value of the gc.pruneExpire config option was increased. He said that the default setting for this option, 2 weeks, was “more than enough for even the most paranoid user”.

About --cruft, Ævar thought that its purpose was not only to avoid possible repo corruption, but also to allow more aggressive gc (garbage collection).

He also wondered if this question was about large hosting sites like GitHub and GitLab, where git gc is run on live repos, and suggested not to worry in this case, but to take backups.

Jeff King, alias Peff, replied to Ævar saying he was “a bit less optimistic” about the corruption risk decreasing when gc.pruneExpire was increased because there was no atomic view of the ref namespace. So renaming a branch for example was risky because it could be seen as removing a branch and adding a different one by any concurrent process. Such a process could be another push, not just a gc.

Peff also said that using --cruft was not so much about avoiding corruption, but about keeping cruft objects out of the main pack to reduce the cost of lookups and bitmaps, and about avoiding to explode a lot of old objects into loose objects, which could be very bad for performance.

Ævar replied to Peff discussing further when corruption was likely or not to happen, which issues --cruft could help with, and a patch he sent in the past to reduce possible corruption. He also suggested running git gc on the least busy hours of the day.

Later Taylor Blau replied to Ævar and Peff discussing --cruft in the context of single-pack bitmaps or multi-pack (MIDX) bitmaps, and also in the context of GitHub.

In the meantime, Michal Suchánek replied to Ævar’s first email asking what the 2 week default expiration time applied to. He also said that he got corrupted repos with less than 100 users “and some scripting” which went away when gc was disabled.

Peff replied to Michal, saying that the expiration time applied to the mtime on the object file (or the pack containing it), and confirmed that it was “far from a complete race-free solution”.

ZheNing also replied to Michal saying that he preferred “no error at all” to a “small probability of error”.

Michal replied to Peff listing some workflows that are more likely to lead to a corrupt repo, like deleting branches but pushing other branches that are variants of these branches, and different people pushing files from the same external source.

Peff confirmed that these workflows were indeed risky, and detailed a bit further how the race conditions can happen.

ZheNing then replied to Peff asking if there was “an easy and poor performance” way like a lock on a repository to avoid for example concurrent push and gc processes.

Ævar replied that there was no such way but that we should have one. He explained that it could perhaps be done using hooks, like ‘pre-receive’ and ‘post-receive’, when we were sure that all relevant operations were going through these hooks. (For example no local branch deletion should be possible.)

ZheNing and Michal discussed a bit further the details related to how a repo corruption can happen with concurrent push and gc processes, and how that could possibly be avoided.

Developer Spotlight: Teng Long

Who are you and what do you do?

My work is related to R&D efficiency tools development at Alibaba Cloud. Our team have currently built a code hosting service as codeup.aliyun.com which provides free and high-quality code services for Chinese developers on the public cloud. In addition, I used to be a Gerrit contributor, because I wrote Java for nearly 10 years, and this process made me almost forget the C language, LOL.

For the contributions of Git community, apart from me, Jiang Xin (the Git localization coordinator), ZheNing Hu, and Chen BoJun are also in the team.
What would you name your most important contribution to Git?

First of all, I know Git for some years, but I’m new in the community, because Git’s technical depth is obvious which involves algorithms, operating systems, testing techniques, etc. Also, Git has many subcommands, which makes the implementation of Git itself involve many aspects, and I think it is difficult for a new contributor to understand everything, but long-term participation may make you an expert in one aspect of Git. Sadly, my time devoted to the Git community is actually limited.

I contributed a feature last year to allow the git ls-tree subcommand to support the --format option which let you print out the result as you want, this is helpful for some automated tools or scripted work I think. If you want to know about it further, a better way is to read the blog by Taylor Blau.
What are you doing on the Git project these days, and why?

I’ve been following the evolution of the bundle-uri feature recently, I think the idea of this feature is great and attractive. If used properly, it can not only improve the speed of code download in some scenarios, but also reduce the load on the server.

I’m also reading about algorithms related code (like bitmap, multi-pack bitmap, bloom-filter), as I want to know some details about the combination of Git and algorithms. I think it’s interesting.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

We all know that it can be a pain in terms of resource load and cost to provide large-scale Git services. I hope to be able to solve the problem with Git’s storage and computing coupling to let Git be better to integrate with cloud-native architecture. Like, should it be possible to store the refs, loose objects and packs on a Distributed Database？

I think this is one of the future development direction of the Git architecture, starting from lower cost and cloud friendliness. If you want to do these tasks based on Git, you may need to make the internal related implementations more adaptable, which requires a lot of professional work I think.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Maybe introduce a new option --branches in git push to replace --all. Option --all means to push all branches, --tags means to push all tags, but many people misunderstand it (at least those around me), because they think --all means to push all the branches and tags together. In fact, I made an RFC patch before, hoping to support the --branches parameter in the first step, and I’ll consider following up with this patch.
What is your favorite Git-related tool/library, outside of Git itself?

I prefer git-repo which supports doing code reviews or pull requests on the client, just like using a native Git subcommand.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Still memorable when my first commit was merged in, even though it was a small fix. This process made me understand that contributing to Git is completely different from other workflows, and the process and results both feel good.
What is your toolbox for interacting with the mailing list and for development of Git?

First, I use https://public-inbox.org/git/?q=a%3Adyroneteng to check if there is any new mails related to me.

Then, I’ve been using git format-patch to create patchsets and git send-email to post them, and git am for local reviews. I don’t know if there’s a better way, but it seems to be enough for me.
What is your advice for people who want to start Git development? Where and how should they start?

Contributing to Git is not an easy task, after all, you are working with other excellent contributors in the community, but continuous understanding and participation may make you an expert in a certain direction.
If there’s one tip you would like to share with other Git developers, what would it be?

I think it would be “get used to the process of contribution slowly”.

The review process is sometimes frustrating, but most of the suggestions by reviewers are still valuable; you can learn a lot from the process, then you can better participate in the next contribution.

Releases

Git 2.39.1 and others
Git for Windows 2.39.1(1)
libgit2 1.5.1
GitLab 15.8 15.7.5, 15.6.6, and 15.5.9, 15.7.3, 15.7.2, 15.7.1
Bitbucket Server 8.7
GitHub Enterprise 3.7.4, 3.6.7, 3.5.11, 3.4.14, 3.3.19, 3.7.3, 3.6.6, 3.5.10, 3.4.13, 3.3.18
GitKraken 9.0.1
GitHub Desktop 3.1.5, 3.1.4

Other News

Various

Git security vulnerabilities announced that affect versions 2.39 and older. Fixes were authored by engineers from the GitLab Security Research Team, as well as GitHub Engineers, and members of the git-security mailing list.
- Two of three vulnerabilities were found as part of an audit of the Git codebase conducted by X41. This audit was sponsored by the Open Source Technology Improvement Fund (OSTIF). X41 have also published information about this Security Audit of Git.
- Git security audit: Inside the hunt for - and discovery of - CVEs by Joern Schneeweisz on GitLab Blog.
- This Week In Security: Git Deep Dive, Mailchimp, And SPF by Jonathan Bennett on Hackaday, and A security audit of Git brief on LWN.net.
GitHub Sponsors will stop supporting PayPal, starting on February 23, 2023.
GitHub is sunsetting Subversion support. On January 8, 2024, GitHub will remove support for Subversion.
XetHub raises $7.5M for its Git-based data collaboration platform by Frederic Lardinois on TechCrunch.

Light reading

Beyond Git: The other version control systems developers use by Ryan Donovan on The Overflow (stackoverflow.blog).
Never write a commit message again (with the help of GPT-3) by Roger Zurawicki on his blog (though read the proposed commit message before accepting it, please).
Sending a kernel patch with b4 (part 1) by Konstantin Ryabitsev (sending patch with b4 is described in Contributor overview section of the tool documentation).
- Introducing b4 and patch attestation was mentioned in Git Rev News Edition #61.
The GitHub Silverware Drawer Dilemma, Or: Finding Active Repository Forks by Maya Posch on Hackaday points to projects that help to find the most active fork.
7 Git articles every open source practitioner should read by AmyJune Hineline from RedHat on OpenSource.com.
Understanding Git through images by kataoka_nopeNoshishi on DEV.to.
Querying the GitHub archive with the ClickHouse Playground by Simon Willison on Simon Willison’s TILs (Today I’ve Learned).
7 tips for improving your productivity with Git by Daniel Genezini on his “It works on my machine” blog (also on DEV.to).
Fix that damn Git Unsafe Repository by Rick Strahl on Rick Strahl’s Weblog.
Mastering the Art of Writing Effective Git Commit Messages by Ashish Patel on DEV.to.
11 tips for writing a good Git commit message by AmyJune Hineline from RedHat on OpenSource.com.
20 Git Commands you (probably) didn’t know about by Alicia Sykes on DEV.to.
How to Checkout a Remote Git Branch by Dave McKay on How-To Geek; though the article misses the DWIM git checkout <remote-branch> trick, and does not mention the newer git switch <branch> command as alternative to git checkout <branch>.
Git tutorials - understanding of rebase and merge by Joonhyeok Ahn (Joon) on DEV.to is the final part in the 4 part Git Cookbook series.
Golang (and thus git-lfs) is evil on shitty networks on the Somewhere Within Boredom blog (may be fixed by the time you are reading this).

Git tools and sites

Git-Sim: Visually Simulate Git Operations In Your Own Repos. Run a one-liner git-sim command in the terminal, for example git-sim reset HEAD^ or git-sim merge dev, to generate a custom Git command visualization (.jpg, .mp4) from your repository. Written in Python, available as package on PyPI.
heatwave is a tool to visualize your Git commits with a heat map in the terminal, similar to how GitHub’s heat map looks. Written in Python, also available as package on PyPI.
git-stats is a similar tool to visualize local git statistics, including GitHub-like contributions calendars. Written in JavaScript + HTML, available as npm.js package.
- Note that Git-Stats, also known as GitStats.me, is an unrelated open-source GitHub contribution analyzer as a web service, which was mentioned in Git Rev News Edition #63.
scmrepo by Iterative is a SCM wrapper and fsspec filesystem for Git for use in DVC. Works with multiple backends: pygit2 (libgit2), Dulwich, and GitPython.
- DVC (Data Version Control) was first mentioned in Git Rev News Edition #42.
gptcommit is a git prepare-commit-msg hook for authoring commit messages with the GPT-3 language model. Written in Rust.
Note: you need to ensure you have sufficient credits in your OpenAI account to use it.
There are a few software forges working on implementing ForgeFed and/or ActivityPub federation. ForgeFed (formerly GitPub) is a federation protocol for forge services, first mentioned in Git Rev News Edition #69 in 2020.
- Vervis is a project hosting and management application, with a focus on software projects and decentralization. Self-hosted on the https://vervis.peers.community instance. Supports Git and Darcs, and ForgeFed/ActivityPub federation. It is currently very much a work in progress. Written in Haskell.
- ForgeFlux is API-space software forge federation with ForgeFed for Gitea, Sourcehut, GitLab, and GitHub. Repositories are (also) hosted on GitHub. Note: the project homepage on https://forgeflux.org/ seems to be down at the time of writing.
- Forgefriends is a self-hosted forge federation project, which purpose is to allow every Free Software developer to use their favorite forge to contribute to software projects hosted on other forges. Forgefriends is written in Go to share code with Gitea, and synchronization is done via the W3C ActivityPub protocol. It is currently in pre-alpha stage.

Credits

Git Rev News Edition 94 (December 31st, 2022)

chriscool — Sat, 31 Dec 2022 11:06:51 +0000

Git Rev News: Edition 94 (December 31st, 2022)

Welcome to the 94th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of November 2022 and December 2022.

Discussions

General

What’s cooking in git.git (Nov 2022, #05; Tue, 22)

Junio Hamano, the Git maintainer, sent one of his usual “What’s cooking in git.git” emails to the mailing list. At the beginning of the email though he thanked everybody for “successfully concluding the ‘bus factor’ exercise”.

It was indeed the first time in a few years that he temporarily handed over the maintainership of the project to someone else, in this case Taylor Blau, as he was having a vacation. It’s called a ‘bus factor’ exercise as it’s supposed to make a transition smoother in case the current maintainer would be “hit by a bus”.

The previous “What’s cooking in git.git” email had been sent a few days before by Taylor, who also thanked everyone, as he saw that Junio was back online again.

Support

Git Bug Report: out of memory using git tag

Martin Englund sent a bug report to the Git mailing list saying that after creating a signed tag using a ssh-agent key, he ran the following command that should have shown the body part of the tag contents:

git tag -l --format '%(contents:body)' v0.6.1

But instead of displaying anything, the command crashed with:

fatal: Out of memory, malloc failed (tried to allocate 18446744073709551266 bytes)

Peff, alias Jeff King, thanked Martin for the report and said he had found the function where the crash happened and the reason why it happened. He also provided minimal reproduction instructions as well as the commit that introduced the bug, and he put the author of that commit in CC of his email.

Philippe Blain, the author of the commit, thanked Peff for the information and said he would try to find a fix for the bug.

Peff replied to Philippe that after sleeping on the issue, he fully understood what happened. He said there were actually two closely related bugs and he was sending 2 patches to fix them both.

The first patch was a fix for cases where there was no blank line between the subject of a tag and the signature in it, and when the signature also contained no blank line. Such signatures could be generated by ssh.

In such cases the code wasn’t properly detecting the start of the signature and was instead using the end of the commit. When computing the signature length, this would give a negative value, which was then converted to a huge value as the variable for the signature length used an unsigned type. In turn when allocating memory for the signature, this would lead to the crash as it wasn’t possible to allocate the requested amount of memory for it.

The second patch fixed a similar bug that occurred when there was a blank line in the signature but not before it, and this blank line ended with both the CR (Carriage Return) and LF (Line Feed) characters instead of only the latter.

In that case, the start of the signature was also not properly detected, so a negative value was assigned to the variable for the signature length, which led to a crash when allocating memory for the signature.

Both patches are very well explained in long commit messages. This prompted Elijah Newren to reply to Peff joking about the fact that Peff’s patches didn’t set new records for the ratio of commit message lines to changed code, as a previous patch from Elijah contained 96 lines of explanation to describe a one-line fix.

In the same spirit, Peff replied to Elijah providing a script to find the commit with the highest ratio between lines of explanations in the commit message and the lines in the patch. He said that the script would show “a few in the 100’s”.

Ævar Arnfjörð Bjarmason then replied to Peff contesting the method used in Peff’s scripts and suggesting computing “the Levenshtein distance of the pre- and post-image”, and then using that distance to commit message length instead of the previous ratio, which would find other winners.

Elijah ended this subthread of discussion about the biggest comment to code ratio in a commit in the Git repo with:

“Hehe, my offhand joke started a contest over the whimsical question of who’s the most long-winded. I think my work here is done. :-)”

Eric Sunshine, after reviewing Peff’s patches, commented that they were well explained and that he found no suggestion to improve on them.

Philippe agreed with Eric that the patches were very well explained and asked Peff about the case where there would be both no blank line and lines terminated with both CR and LF in the tag. Peff then confirmed that this would be properly handled by his first patch.

Taylor Blau, who was handling the maintainer’s role in the project at that time, as Junio Hamano was having a vacation, also agreed that the patches were very well explained, and agreed to take them. The patches were then merged and part of the Git v2.39.0 feature release.

Developer Spotlight: ZheNing Hu

Who are you and what do you do?

My name is ZheNing Hu, and I am a participant in the GSOC 2021 Git community. Currently I am interning at Alibaba (China).
What would you name your most important contribution to Git?

When I used git shortlog --author="ZheNing Hu" to look at the patches I contributed, I was ashamed to find that my patches are quite small and simple, because I’m more of a Git learner right now 😄.

If I had to pick one, I’d say it’s adding the --trailer option to git commit. It is very convenient to add something like “Signed-off-by”, “Reviewed-by” at the end of the commit message.
What are you doing on the Git project these days, and why?

Recently I’ve been working on implementing a --scope option for git diff and other Git commands. It tries to limit the scope of the file path to the sparse specification.

The reason I wanted to implement this feature is that I was researching how monorepo users collaborate and discovered that git pull might download Git objects outside of the sparse specification. Meanwhile, Elijah Newren is contributing the technical documentation of git-sparse-checkout [ source ], the article details how other Git commands should properly recognize sparse-checkout, and suggests implementing the --scope option, which I think will solve the problem I encountered above, so I hope to implement it.

This patch was put on hold by me for a while, as no one seemed to review it.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’d like to have a well-developed concurrency model on the Git server side. See “Question: How to execute git-gc correctly on the git server” for more details.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

git checkout. It can be used to switch branches or restore working tree files, I think these two functions are somewhat coupled. I don’t know if git switch and git restore would be perfect replacements for it.
What is your favorite Git-related tool/library, outside of Git itself?

scalar. Now I really like to use scalar to download Git repositories to save time.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Mainly during GSOC, my mentor Christian Couder and many people in the Git community helped me, and I learned how to participate in open source for the first time. It was a great experience to be brave and discuss technology with people from all over the world.
What is your toolbox for interacting with the mailing list and for development of Git?

GitGitGadget. It has a clean commit process, and it runs GitHub action to help me find out if my patch is buggy before committing to the community.
What is your advice for people who want to start Git development? Where and how should they start?
1. First become its user
2. Understand its principles through the documentation
3. Read the source code to understand the general structure of the project
4. Understand some sub-modules of the project by solving some problems
5. Learn from others with an open mind
If there’s one tip you would like to share with other Git developers, what would it be?

Stay curious about technology.

Releases

Git 2.39.0, 2.38.2, 2.39.0-rc2, 2.39.0-rc1
Git for Windows 2.39.0(2), 2.39.0(1), 2.39.0-rc2(1), 2.39.0-rc1(1)
GitHub Enterprise 3.7.2, 3.6.5, 3.5.9, 3.4.12, 3.3.17
GitLab 15.7 15.6.3, 15.5.6, 15.6.2, 15.6.1, 15.5.5 and 15.4.6
GitKraken 9.0.0
Sourcetree 4.2.1
git-assembler 1.3

Other News

Various

Siddharth Asthana, who worked on Git during his GSoC 2022 for GitLab, is looking for a 6-month Engineering internship, either full-time starting from mid-July 2023 or part time starting now. See his resume for more information.
Highlights from Git 2.39 by Taylor Blau on GitHub Blog.
Put glab at your fingertips with the GitLab CLI by Kai Armstrong on GitLab Blog.
Andrew Morton’s first pull request by Jonathan Corbet on LWN.net (from May 2022).
- Git Rev News Edition 14 (April 20th, 2016) mentioned, when describing discussions at the Git Contributor Summit (part 1, about big repos and big files), that Andrew Morton uses (used?) quilt to maintain his “-mm” kernels, and that he sent patches by email.

Light reading

Billions of unnecessary files in GitHub and Git repositories in general, due to missing or lacking .gitignore files. Article by Gabor Szabo on DEV.to (also known as The Practical Dev). There is also some good information in the comments.
What are your git aliases? by Jose Angel Munoz on DEV.to.
How to Close a Pull Request - Merge Commit vs Squash vs Rebase on GitHub by Leonardo Montini.
What is GitOps? on GitLab.
- The topic of GitOps was mentioned in Git Rev News Edition #42, #43, #61, #62, and #89
GitOps viewed as part of the Ops evolution by Viktor Nagy o GitLab Blog (2021).
A meta talk about Git strategies for deployment (GitOps-like), by Morten Olsen on DEV.to.
Rebases in Git and why you shouldn’t be afraid of them by Marcin Wosinek for How to dev (also reposted on DEV.to).
Take advantage of Git rebase by Christian Couder on GitLab Blog.
Split a commit into 2 commits with git rebase by Sean Larkin on DEV.to.
Minimum Viable Git for Trunk-based Development by Eli Schleifer on trunk.io blog (a Medium-based blog).
- Trunk Based Development was mentioned directly in Git Rev News Edition #24 and #73.
- Patterns for Managing Source Code Branches by Martin Fowler, mentioned in Git Rev News Edition #63, describes Trunk-Based Development in the section Looking at some branching policies.
Benefits of Using Pull Requests for Collaboration and Code Review by Fatos Morina on NVIDIA Developer Technical Blog.
How to revert a merge commit then merge again by Jb Rocher on his blog (also on DEV.to).
Git worktree by Flavio Poletti (@polettix) on his ETOOBUSY blog.
Git Notes: Git’s Coolest, Most Unloved Feature by Tyler Cipriani on his blog.
- You can find various uses of the Git notes feature mentioned in Git Rev News: marking test suite successes in #6, and maintaining a high quality change log in #34.
- git-appraise, a distributed code review system for Git repos using git notes was mentioned in Git Rev News Edition #11.
Learn Git: 3 commands to level up your skill by Dwayne McDaniel on Opensource.com.
Code version best practices with clean commit formats, following Angular commit convention guidelines, by Chaitanya S. on Halodoc blog.
- Conventional Commit specification was first mentioned in Git Rev News Edition #52.
- commitlint was first mentioned in Git Rev News Edition #81, Commitizen in #72, Husky in #63, and conventional-changelog in #81.
Resolving Merge Conflicts with Visual Studio Code by Leonardo Montini (also on This is Learning DEV.to blog).
30+ Commonly Asked Git Interview Questions on InterviewBit.
Extremely Linear Git History, where first commit in a repo hash a hash that starts with 0000000, the second commit is 0000001, the third is 0000002, and so on is possible with extremely-linear (aka git linearize) tool. Article and tool by Gustav Westling. ☺
- Git Rev News Edition #24 mentions in passing the git-sham tool, which can be used to produce subsequent commits with SHA-1 identifiers beginning with subsequent numbers - but the tool doesn’t seem to exist anymore at its original URL.

Git tools and sites

git-credential-oauth is a Git credential helper that securely authenticates to GitHub, GitLab, BitBucket and other forges using OAuth.
semantic-release (documentation) is a fully automated version management and package publishing Node.js tool.
Release Please is a Node.js tool that automates CHANGELOG generation, the creation of GitHub releases, and version bumps for your projects; it does so by parsing your Git history and looking for Conventional Commit messages.
gitignore.io by Toptal is a service that creates useful .gitignore files for your project.
- github/gitignore is GitHub’s collection of .gitignore file templates.
- Atlassian’s Bitbucket has a .gitignore tutorial.
- GitLab provides a .gitignore API on all tiers.
- gig, a Node.js command-line tool for quickly setting up .gitignore files, which uses GitHub’s gitignore repository for gitignore templates, was mentioned in Git Rev News Edition #6.
- .gitignore Generator extension for Visual Studio Code, which uses the gitignore.io API, was mentioned in Git Rev News Edition #57.
Diffchecker.com is an online service that will compare text to find the difference between two text files; there is also an option for comparing images, PDFs, and spreadsheets in xls/xlsx/xlsm/xlsb, csv, txt, dif, and ods formats. There are also commercial Diffchecker Pro service and Diffchecker Desktop apps.
OpenGitOps is a set of open-source standards, best practices, and community-focused education to help organizations adopt a structured, standardized approach to implementing GitOps.
- GitOps.tech, a similar site that aggregates the essence of GitOps (and includes free GitOps: Cloud-native Continuous Deployment e-book, published via Leanpub), was mentioned in passing in Git Rev News Edition #62.
Semantic Versioning Specification (SemVer) is a simple set of rules and requirements that dictate how version numbers are assigned and incremented.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from ZheNing Hu, Philip Oakley, Junio Hamano and Mirth Hickford.

Git Rev News Edition 93 (November 30th, 2022)

chriscool — Wed, 30 Nov 2022 11:06:51 +0000

Git Rev News: Edition 93 (November 30th, 2022)

Welcome to the 93rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of October 2022.

Discussions

Reviews

[PATCH] archive: add –recurse-submodules to git-archive command

Heather Lapointe sent a patch to the mailing list that enabled git archive to also include submodule contents in the archives it produces.

She said she was inspired by a GitHub issue more than 160 upvotes and thought the implementation wouldn’t be too difficult as most of the plumbing was already in place.

One of the trickier parts was changing the read_tree() function to support other repos than the current one by not using the the_repository global variable.

Heather soon sent a version 2 patch series. This patch series contained only 2 patches. The first one was identical to the one previously sent, while the second one fixed a submodule traversal bug in read_tree() introduced by the first patch.

René Scharfe replied to Heather, noticing that the cover letter of the patch series had a TODO list with a number of items, most of which seemingly already addressed. As the stats in the cover letter showed 16 files changed, 269 insertions, and 96 deletions, he said it was a bit much for a few patches, and suggested splitting them.

Heather replied to René that the TODO list came from GitGitGadget. And René found that this tool was using an HTML-to-text converter that doesn’t handle checkboxes nicely by default. René and Heather then discussed how to split the patches, and a bit how the first patch was implemented.

Heather then sent a version 3 of her patch series that split her previous patch series into 8 patches.

Junio Hamano, the Git maintainer, along with Glen Choo, Jonathan Tan, Phillip Wood and Ævar Arnfjörð Bjarmason all commented on some of the patches in this series and suggested small improvements.

The Review Club selected this patch series to be reviewed by participants on Wednesday October 26, and participants generally agreed that “this is a really well-structured and easy-to-follow series :)” and that “as far as new contributions go, this is really good”.

Unfortunately it looks like Heather has been swamped with her own work and didn’t have time to send a new version yet. Hopefully though we will get this very requested feature soon.

As a side effect of the discussion, GitGitGadget formats checkboxes nicely now.

Developer Spotlight: Bagas Sanjaya

Who are you and what do you do?

I’m Bagas Sanjaya. I’m currently unemployed (due to my autistic condition that makes working formally isn’t the nice option for me).
What would you name your most important contribution to Git?

Adding the INSTALL_STRIP variable when installing Git from source (with help from other Git developers due to lack of coding experience).
For the benefit of the readers, is it possible for you to elaborate a bit on what the INSTALL_STRIP variable would help them with?

Typically users install Git from binary package provided by the distribution. For those who wish to install from source, they can install build-time dependencies first, then simply do make && make install. However, it will install Git binaries with debugging info, which can take a lot of space. In addition, many Unix systems have install(1) that has an option to automatically strip debugging info during installation. That’s why INSTALL_STRIP is introduced; if supported, users can run make INSTALL_STRIP=-s install to install stripped binaries.
What are you doing on the Git project these days, and why?

I’m mostly translating po strings in recent days. Otherwise I’m hacking on Linux kernel documentation.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

As an autistic man, I’d like to meet developers who can accommodate my special needs (often different from neurotypical people) so that I can thrive my living.
It is good to know that you would like to meet compassionate developers. Is it possible for you expand a bit on what you would like to change / enhance in Git when you get a team of such developers for a year?

I think more on communication. Sure, communicating with email makes life easier for autistic developers (less physical interaction). However, autistic people have different ways of communicating. For me, I need a lot of time to process the information from a mailing list and formulate the wording (which is due to comorbid ADHD). Thus, the community expectation should have been adapted to individual needs, e.g. by being more explicit on explanation of code of conduct when a new developer is contributing. If he/she doesn’t understand the CoC, he/she can proactively ask the community about points that he/she doesn’t understand.

In summary, besides adaptation from the community, there must be initiatives from developers themselves.
What is your favorite Git-related tool/library, outside of Git itself?

Gitea. I deployed the server application to the LXD instance on my laptop as repository mirror when I push my favorite repos there.
You have experience translating for Git. Is there something that could be done differently to aid with the translation effort?

I think we need something like self-hosted Weblate to enable anyone with translation skills to easily submit translated strings. But honestly deploying one is tricky; I tried to deploy Weblate but couldn’t get strings from Git source code to be available for translation on the interface.
How does your mailing list workflow look like?

Simplicistic. After configuring git send-email to send through outgoing relay of your mail provider and your email clients to send plain text email, unaltered (no line wrapping, intact tabs and spaces), you can contribute by sending patches with the former and reviewing with the latter.
What is your advice for people who want to start Git development? Where and how should they start?

You need to find a joy in application development. If it doesn’t makes you enjoy, you may need to take a break or find something else.
If there’s one tip you would like to share with other Git developers, what would it be?

As autistic, special interest fascinates me. You need to find one in this project, while staying up-to-date with the general picture.

Releases

Git 2.39.0-rc0
Git for Windows 2.39.0-rc0(1)
GitLab 15.6 15.5.4, 15.4.5, 15.5.3, 15.5.2, 15.4.4, and 15.3.5
Bitbucket Server 8.6
Gerrit Code Review 3.4.7, 3.4.8, 3.5.4, 3.6.3, 3.7.0
GitHub Enterprise 3.7.1, 3.6.4, 3.5.8, 3.4.11, 3.3.16, 3.7.0
GitKraken 8.10.3, 8.10.2
Tower for Mac 9.1

Other News

Various

Shaoxuan Yuan, who participated in the GSoC 2022, is looking for a full time internship from mid-June 2023 to October 2023 or a part-time one starting now. See his resume for more information.

Light reading

Working with stacked branches in Git is easier with --update-refs (an option which was included in Git 2.38, in October 2022) by Andrew Lock on his blog, .NET Escapades.
Bringing revsets to Git by Waleed Khan (@arxanas) describes how one can use the git-branchless suite of tools (mentioned in Git Rev News Edition #76 and #90) and Mercurial’s revset notation to form complex queries about a repo, display their results (for example in a graph view), rebase changes using “patch-stack” workflow, and improve testing.
Sapling: Source control that’s user-friendly and scalable by Durham Goode on Engineering at Meta (Facebook) blog. At this point, only the client side of the system has been released.
You can find some comments about it at:
- Meta’s Sapling source-code management system on LWN.net.
- Sapling: A new source control system with Git-compatible client on Hacker News.
Git evolve: tracking changes to changes (free preview link) by Jonathan Corbet on LWN.net.
Using gitStream for ‘Continuous Merge’: automatically approving safe PRs, assigning reviewers, estimating review time, and more by Jake Lee on his blog.
My favorite Git tools by Dwayne McDaniel on Opensource.com.
Git concepts in less than 10 minutes by Dwayne McDaniel on Opensource.com.
#gitPanic - Interactive Rebase by Abbey Perini on DEV.to (part of the gitPanic series).
Top 12 Advanced Git Commands To Know by El-Glory Oriabure on OpenReplay blog, with admittedly some pretty basic commands in there.
Light Git repository checkout with git sparse-checkout by Flavio Poletti (@polletix) on his ETOOBUSY blog.
The Perfect Commit by Simon Willison on his Weblog.
New Git guidelines: We have switched to Conventional Commits by Malte Riechmann for visuellverstehen on the Happy Coding blog. (post is also available on DEV.to). The Conventional Commits specification was first mentioned in Git Rev News Edition #52.
How to Write the Perfect Commit Message by Bruno Brito on Tower’s blog.
Why You Should Use a Git Client by Bruno Brito on dev.to.
Jakub Kozłowski tweeted that Git conflict markers are parsed as valid Scala code, though you need to add some appropriate definitions, now available as a scala-git-markers library, for it to run ;-). Explained in more detail in his video on YouTube.

Easy watching

Understanding Git Flow: A look at the operations of Git Flow through the Flying Logic visualisation of the branches and release process. The channel also has Git visualisations of Collaboration, merge and rebase, detached HEAD, and ‘What’s a DAG’.

Git tools and sites

Sapling SCM is a scalable, user-friendly source control system that supports cloning and interacting with Git repositories, and can be used by individual developers to work with GitHub and other Git hosting services.
Stacked Git, StGit for short, is an application for managing Git commits as a stack of patches (with its first release in 2005, it is almost as old as Git itself). StGit was mentioned by Yann Dirson in the Git Rev News Edition #74 developer spotlight.
Mergify is a tool to merge changes from a branch one commit at a time, most useful when merging changes to a highly diverged fork of a project.
- Note that there is also Mergify.com, mentioned in Git Rev News Edition #87, a web service free for open-source projects for automatizing pull requests and securing the code merge using a merge queue.
git-mergify-rebase is a replacement for mergify, written using git rebase for better performance, supporting most of features of the original.
Nx is a next generation build system for Node.js, with first class monorepo support and various integrations. Listed in the tools section of monorepo.tools, a site mentioned in Git Rev News Edition #84.
gitStream by LinearB is a GitHub app that aims to improve the pull request review process.
tweets is @bcrypt’s janky twitter “replacement”, using Git commit messages and GitHub for “microblogging”; see the announcement on Twitter ;-). Written as set of Bash scripts and a Makefile.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Bagas Sanjaya, Bruno Brito, Glen Choo and René Scharfe.

Git Rev News Edition 92 (October 26th, 2022)

chriscool — Wed, 26 Oct 2022 11:06:51 +0000

Git Rev News: Edition 92 (October 26th, 2022)

Welcome to the 92nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of October 2022.

Discussions

General

Git participated in GSoC (Google Summer of Code) 2022

The following contributors have successfully passed their final evaluation and published a final report:
- Shaoxuan Yuan worked on the More Sparse Index Integrations project project. He was co-mentored by Derrick Stolee and Victoria Dye.
- Abhradeep Chakraborty worked on the Reachability bitmap improvements project. He was co-mentored by Kaartic Sivaraam and Taylor Blau.
Also Siddharth Asthana successfully participated in GSoC 2022 for GitLab (instead of Git) and contributed to Git as part of his work on the Add Support for Mailmap project. He was co-mentored by John Cai and Christian Couder.

Congratulations to these contributors and their mentors!

Reviews

[PATCH] fuzz: add basic fuzz testing for git command

Arthur Chan sent a patch to add basic fuzz testing to Git. The patch added a set of helper functions in some fuzz-cmd-base.{h,c} files and a demonstration entry point (called fuzzing target) for LibFuzzer or similar tools to inject fuzzed data into git status in a fuzz-cmd-status.c file.

Ævar Arnfjörð Bjarmason replied to Arthur. He suggested coding style improvements to better match our style as well as taking a look at the infrastructure code we already have for fuzzing. He also wondered if existing code - that is, APIs for file generation and the shell-based infrastructure in the t/ directory - could not be used for fuzzing, too.

Arthur replied that he couldn’t find existing infrastructure code for fuzzing and that he was confused about avoiding the system(3) calls as they were needed to reset the state of the repo after each round of fuzzing, and the LLVM oss-fuzz library required such resetting logic to be included in the C code.

Junio Hamano, the Git maintainer, also replied to Arthur saying that, before adding new fuzzing infrastructure, existing one should be moved into a new fuzz/ directory. Junio also suggested some coding style improvements and commented on possible performance and correctness issues.

Arthur replied to Junio that he implemented the suggested changes in a version 2 of the patch that he was preparing, and then sent this version 2 to the mailing list.

This version of this patch indeed moved some existing fuzz-commit-graph.c, fuzz-pack-headers.c and fuzz-pack-idx.c files into a new oss-fuzz directory. The patch still added the new fuzzing infrastructure that was in the previous version, though a lot of the issues that had been pointed out were fixed.

Junio replied that it was better to have the “cleaning up of existing stuff” and “addition of new stuff” split into two separate patches instead of having everything in the same one.

Arthur agreed to split the move of the existing fuzzing infrastructure into a separate preparatory patch called “fuzz: reorganise the path for existing oss-fuzz fuzzers” that he later sent to the mailing list.

Junio reviewed the preparatory patch and found that some changes to the .gitignore file were likely missing. He also asked how the fuzzing should be launched.

Arthur replied agreed that changing the .gitignore file was needed and said that he got privately in touch with people from oss-fuzz targeting Git who had implemented the existing fuzzing. He also said that a Dockerfile and build script prepared for Git would launch the fuzzing.

Arthur then sent a version 2 of the preparatory patch with a few small fixes and the .gitignore changes that Junio suggested. Soon after he sent a version 3 with very minor changes compared to version 2.

Ævar replied to this new version suggesting some commit message improvements to better explain the patch purpose as well as creating oss-fuzz/.gitignore instead of changing the .gitignore file at the root of the repository.

Arthur sent a version 4 with the suggested changes.

Junio commented a bit on how to make sure people get CC’ed in the emails sent by GitGitGadget but was happy with the patch itself, which has since been merged into the master branch.

We are looking forward to even more fuzzing infrastructure improvements in the near future.

Releases

Git 2.38.1 and others, 2.38.0
Git for Windows 2.38.1(1), 2.38.0(1)
GitHub Enterprise 3.7.0, 3.6.3, 3.5.7, 3.4.10, 3.3.15, 3.2.20
GitLab 15.5.1 15.5, 15.4.3, 15.4.2, 15.4.1, 15.3.4, and 15.2.5
Bitbucket Server 8.5
Gerrit Code Review 3.4.6, 3.5.3, 3.6.2
GitHub Desktop 3.1.2, 3.1.1, 3.1.0
Tower for Windows 4.0 (blog post)

Other News

Events

The recorded talks of Git Merge 2022 are now live.
The summary of Git Merge 2022 can be found in the Git Merge 2022 – that’s a wrap! blog post by Lee Reilly on the GitHub Blog.

Various

Git security vulnerabilities announced (CVE-2022-39253, and CVE-2022-39260) that affect Git’s --local clone optimization (important when cloning with --recurse-submodules from untrusted repositories) and git shell’s interactive command mode. Fixed in Git 2.38.1.
Highlights from Git 2.38 by Taylor Blau on the GitHub Blog.
- See also Git 2.38 Adds Microsoft’s “Scalar” Repository Management Tool by Michael Larabel on Phoronix.
Cybernews research team discovered millions of .git folders exposed to public.
A Code Review Handbook published by Sledgeworx Software.

Light reading

Setting Up GPG on Windows (The Easy Way) by Bruno Brito on Tower’s blog.
Our Favorite Tower Features by Florian Albrecht on Kaleidoscope’s blog.
The Story of Scalar by Derrick Stolee and Victoria Dye on the GitHub Blog.
Literally the smallest changeset possible created: Fix: remove a ZERO WIDTH NO-BREAK SPACE in front of an inline literal.
VS Code “Timeline” feature — Your local version control system by Amit Merchant.
Turn around your Git mistakes in 17 ways by Smitter hane on DEV.to.
GitHub’s Missing Merge Option by Tyler Cipriani, explaining the conflict between team “git log should be clean” vs. team “git log should have an accurate history” and the consequences for GitHub users.
Take advantage of Git rebase by Christian Couder on the GitLab blog.
Speed up your monorepo workflow in Git by John Cai on the GitLab blog.
- See also Scaling Git’s garbage collection, mentioned in Git Rev News #91 and Scaling monorepo maintenance, mentioned in Git Rev News #75.

Git tools and sites

focus is a tool to manage Git sparse checkouts derived from the Bazel build graph.
Goblet is a Git proxy server that caches repositories for read access, which is intended to be used as a library. Created at Google as 20% project (with glue code for googlesource.com) as google/goblet, and also used in a modified form at Canva as canva-public/goblet.
- A different Goblet was some time ago a web frontend for Git repositories in Python, using libgit2 and Flask; the seveas/goblet repository has been archived by the owner.
nb is a command line and local web note-taking, bookmarking, archiving, and knowledge base application with Git-backed versioning and syncing.
The Git Reference site is meant to be a quick reference for learning and remembering the most important and commonly used Git commands, but it can also be used as a tutorial. Every page will also link to more in-depth Git documentation.
email + git = <3: Learn to use email with Git! is a guide to contributing to email-driven projects like the Linux kernel, PostgreSQL, or Git. Covers various operating systems and distributions.

Credits

Git Rev News Edition 91 (September 30th, 2022)

chriscool — Fri, 30 Sep 2022 11:06:51 +0000

Git Rev News: Edition 91 (September 30th, 2022)

Welcome to the 91st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of September 2022.

Discussions

General

Git Merge conference and Contributor’s Summit

The Git Merge conference happened on September 14th and 15th. On the afternoon of the first day there were optional workshops and the Git Contributor’s Summit, while the main conference took place on the second day.

As usual the topics that were discussed during the Contributor’s Summit were proposed and voted on before the summit started. The discussions started with the topics with the most votes.

Taylor Blau sent an email summarizing what happened and asking for feedback, followed by an own email thread for each topic that had a note-taker, starting with the topic’s broken-out notes.
Gerrit User Summit 2022

Gerrit User Summit is the event that brings together Gerrit and JGit maintainers, contributors and users, as an opportunity to network face-to-face and share news and experiences. It is now back on the 10-11 November 2022 in hybrid mode with a physical venue in London at CodeNode and online.

The summit is going to be recorded and published on the GerritForge YouTube channel, together with roundtables and discussions between the community members.

Support

rev-parse: -- is sometimes a flag and sometimes an arg?

Tim Hockin sent an email to the mailing list containing a series of git rev-parse commands with some arguments that he ran on the command line, along with their results and his comments.

First he ran git rev-parse unknown-tag, which errored out after printing unknown-tag. The error message said that unknown-tag is an ambiguous argument and suggested to use -- to separate paths from revisions.

So he tried git rev-parse unknown-tag --, which just errored saying that unknown-tag was a bad revision, as expected.

Unfortunately when he then tried git rev-parse HEAD --, there was no error, as expected, but instead of printing only the SHA1 hash corresponding to HEAD, the command also printed -- on its own line after the SHA1 hash.

This made Tim wonder why -- was treated as a regular argument. He looked at Git source code and said that it seemed intentional to treat it that way, but he didn’t understand the reason.

Junio Hamano, the Git maintainer, replied that git rev-parse was mostly a “plumber” command designed to be used by higher level “porcelain” commands. By default, it should be able to “parse” command line arguments, and then dump them all to its output after translating “revs” into raw object names (SHA1 hashes).

As -- is a valid option for “porcelain” commands or scripts that would use git rev-parse to parse their command line arguments, it makes sense for git rev-parse to just pass -- along.

Tim then asked if there was “a more friendly way” to do what he wanted to achieve. But Junio replied that it wasn’t clear what Tim actually wanted to do.

Tim replied that his goal was to convert a string that could contain a tag name, a branch name, or a SHA1 hash (abbreviated or not) into a canonical SHA1.

Junio suggested using git rev-parse --verify <string>, as it would either convert <string> into an object ID (a SHA1 hash by default), or it would error out. Junio also mentioned that the “EXAMPLES” section has more elaborate examples.

brian m. carlson chimed in to say that git rev-parse --verify <string> would print a full object ID whether it exists in the repo or not, if <string> already contains one (for example, the all-zeros object ID). He suggested using git rev-parse --verify <string>^{object} if Tim wanted to also verify that the object exists.

Tim thanked brian and Junio saying that their answer helps a lot.

Developer Spotlight: Jeff King (alias Peff)

Who are you and what do you do?

My given name is Jeff, but most people call me Peff. Even in real life. I’ve been working on Git since early 2006. For a while it was for fun and to scratch my own itches (and maybe to avoid doing my school work), but I joined GitHub in 2011, where my job was mostly about improving Git. I stopped being a full-time employee earlier this year, but I’m still working a few hours a week on Git.
How has your journey been as a long-time Git contributor? Do you happen to have any memorable experience w.r.t. contributing to the Git project?

One thing I’ve found with contributing to Git is that it sneaks up on you over time.

I still remember one moment in 2008 or 2009. In my mind, Git was something I did to procrastinate on “real” work. Shawn Pearce was organizing an in-person meeting of developers, and emailed me specifically to say that I was one of the core developers and should consider coming. I was really confused. Wasn’t this just a thing I did in my spare time? But running git shortlog showed that I was one of the top few contributors. That really changed my mindset; I realized I was part of a larger community, and that it was something I did care about.

And I have that same sense looking at how far Git has come. Day to day (and especially when you’re fixing a bug in code from 2005) it can seem like nothing changes. But when I look back over the span of 10 or 15 years, I’m amazed at the progress. Not just in terms of features in Git, but at the overall development process. The way we work and communicate has matured so much in that time. Some of that is from technical tools (new Git features, new internal APIs and data structures to avoid whole classes of bugs), but some of it is in what the people do. In my opinion, our standards for testing and commit messages have gone up considerably over the years.
Git Merge got over a few days ago. Any takeaways from the conference that you would like to share?

To me, the most important part of Git Merge is making connections between developers. I’m not convinced that sticking 30 people in a room is the best way to have a technical discussion, and the real work later happens solo, or on the list. But I think seeing people in person, and especially chatting with them over lunch, etc, is so helpful to that later work. We all know intellectually that there’s another person on the end of every email, but I think having met them face to face helps us empathize at a more gut level.

Of course, there were some talks, too. I tend to prefer the more technical ones, but being so involved in Git development, there doesn’t tend to be anything too surprising for me there. I thought the talks from Taylor and Elijah were nice dives into new technical material (though they both also have great blog posts that go even deeper!). Martin’s Jujutsu talk gave a lot of food for thought on different ways for people to interact with Git.
Could you share a few words regarding your experience while you were a member of the Git PLC?

I was the person who led the initial effort in 2010 to join Software Freedom Conservancy. We had gotten some money for the project as part of Google’s Summer of Code program. It was being passed around like a hot potato (between countries, even!) as somebody took responsibility for handling GSoC each year. I don’t even want to think of what we were supposed to do with it, tax-wise, but we knew it would be better with some actual structure. So that led to us joining, which led to the PLC as committee in control of the project as an entity (and the money), and that led to handling more assets (the git-scm.com domain, donated hosting agreements from various places, the trademark).

Since the Conservancy entity isn’t directly related to code development, being on the PLC is long periods of nothing, punctuated by big threads full of boring non-coding stuff. Some of it is fun-ish, like handing out travel funds so people can come to Git Merge. Some of it I found very tedious, like discussing trademark enforcement, or code of conduct issues. I was happy to serve on the PLC for many years, but I’m also happy that other people are doing that work now.
What would you name your most important contribution to Git?

I think my biggest contribution is not any one thing, but rather being there for all of the things. There’s hardly a C file in the repository that I haven’t touched at some point, and when fixing a bug I’d often try to find solutions we could apply to the whole code base (e.g., improving an API to be less error-prone and using it consistently in other callers).

I do sometimes work on bigger features. One of the earliest things I did after starting at GitHub was overhaul our HTTP authentication and introduce the credential-helper protocol. I occasionally see other tools using a similar protocol, proving that it was either a great idea, or a seductively bad one!
What are you doing on the Git project these days, and why?

One of my favorite things in Git is to wake up, read an email on the list that says “why does Git do X when I say Y?”, dig it down to some bug or missing feature, and end up with a nice, tidy patch by lunchtime. Of course it doesn’t always go that way, but I do often enjoy these little fixes. It’s like solving a puzzle.

I also have a backlog of half-finished ideas. Some of them are garbage that I’ll probably throw away, but many of them just need a little polishing. One of them is more tunable knobs for repacking (which has been in use on GitHub’s servers for a few years already!), and another is handling negative commit timestamps (so we can finally import pre-1970 Apollo code).
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Arguably I had that already, so maybe past work speaks for itself. Or maybe I squandered it.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Trees should be sorted in order strictly by name, rather than directories sorting as if “/” was appended. It’s a little thing, I know, but it’s one of the few things that’s really impossible to fix because it’s baked so deep into Git’s logical model.
What is your favorite Git-related tool/library, outside of Git itself?

Definitely tig. Its “blame” functionality, and especially the “re-blame from parent” feature, are so useful. I almost never run a bare git blame.
What is your toolbox for interacting with the mailing list and for developing Git itself?

I read the mailing list via mutt. I keep a local archive which I index with notmuch. I used to actually subscribe to the list, but these days I just pull the archive every few minutes from lore.kernel.org’s public-inbox Git repository.

I do all of my development with a fairly vanilla vim setup. I have a few niceties, like terminal hotkeys to cut and paste object hashes, and a vim function to inline output from a Git command (like converting hashes into --format=reference).

I try to share my scripts when they’re not too gross or specific to my workflows. An example there is contrib/git-jump. I keep some other Git-specific scripts in the meta branch which I check out as the directory Meta inside my Git repository (I stole the name from Junio, who has a similar tree of scripts). I use it to rebase my topics and make my daily-driver build of Git. There’s probably not much of use there for most people, but some of it has led to useful features (e.g., our test suite’s --stress option started as a script there, though SZEDER Gábor did all the heavy lifting to integrate it).
What is your advice for people who want to start Git development? Where and how should they start?

There are a lot of ways to get involved in open source, but I think the best one is scratching your own itch. Pick something you want the tool to do, and work on it. That’s probably harder with Git these days than it was when I started, just because the system is larger and more complex, and so much of the low-hanging fruit has already been picked.

A similar way is just reading the list and looking for bug reports. Once you learn about a problem, then it becomes your itch.

Of course it’s fine to start work on a much larger project if you like. But following my “sneaks up on you” philosophy from above, if you work on enough small things, you will eventually find yourself quite comfortable with the code base, and able to work on larger things.
If there’s one tip you would like to share with other Git developers, what would it be?

Re-read your emails before sending! Obviously it’s nice to catch typos and other simple proofreading errors. But it’s also a final chance to make sure you are saying what you want clearly and concisely, and that you understand what the other person is saying.

I can’t count the number of times that I’ve almost sent out a very confused explanation in a commit message, and upon re-reading realized that not only was there a better way to explain it, but a better way to write the code. It’s also one of the reasons I like writing verbose commit messages. Trying to justify the decisions you’ve made in writing a patch is often the moment you realize that your arguments are weak.

Likewise, there have been many times when I’m about to respond to somebody along the lines of “I think you’re wrong, and here’s why”. And upon re-reading I realize that I did not understand their point in the first place. Of course if everybody remains polite, then hopefully the error works its way to a shared understanding eventually. But besides saving everybody time, catching a misunderstanding before sending means you’re wrong on the Internet one less time!

Of course, ending the interview with this tip gives an almost certain probability that I have a typo somewhere above. So maybe one more tip: be humble. And remember to have fun. Oops, that’s two tips.

Releases

Git 2.38.0-rc2, 2.38.0-rc1, 2.38.0-rc0, 2.37.3
Git for Windows 2.38.0-rc2(1), 2.38.0-rc1(1), 2.38.0-rc0(1), 2.37.3(1)
Bitbucket Server 8.4
GitHub Enterprise 3.6.2, 3.5.6, 3.4.9, 3.3.14, 3.2.19, 3.6.1, 3.5.5, 3.4.8, 3.3.13, 3.2.18
GitLab 15.4 15.3.3, 15.3.2, 15.2.4 and 15.1.6
GitHub Desktop 3.0.8, 3.0.7
Tower for Mac 9.0 (What’s New in Tower 9 video)
Tower for Windows 3.4

Other News

Various

SSH commit verification now supported in GitHub.
1Password now allows you to set up and use SSH keys to sign Git commits.
- See also SSH and Git, meet 1Password, mentioned in Git Rev News Edition #85.
New options for controlling the default commit message when merging a pull request via web interface in GitHub.
Merge commits now created using the merge-ort strategy on GitHub.
35,000 code repos not hacked—but clones flood GitHub to serve malware, and GitHub blighted by “researcher” who created thousands of malicious projects.
Gerrit Code Review v3.7.0 release plan has been published.

Light reading

Scaling Git’s garbage collection by Taylor Blau on GitHub Blog: a tour of recent work to re-engineer Git’s garbage collection process to scale to GitHub’s largest and most active repositories.
A primer on Roaring bitmaps: what they are and how they work by Vikram Oberoi.
- Adding support for Roaring Bitmaps to Git was a part of Reachability bitmap improvements Google Summer of Code 2022 project by Abhradeep Chakraborty, see for example their GSoC Final Report on their Medium blog.
Enable Gitsign Today and Start Signing your Commits with so called keyless signing, that is signing that relies on ephemeral keys. Article by Erika Heidi on DEV.to.
Switching git back to GPG signing from SSH key signing, by Seth Michael Larson on his own blog.
- See also Signing Git Commits with SSH Keys, mentioned in Git Rev News Edition #83.
Git signatures with SSH certificates by Matthew Garrett on his Dreamwidth journal.
Merging two GitHub repositories without losing commit history by Schalk Neethling on Mozilla Hacks blog; a simpler solution might be to use the git subtree command, or use the subtree merge strategy, or the ort merge strategy with subtree[=<path>] strategy option.
.gitignore File – How to Ignore Files and Folders in Git by Dionysia Lemonaki on freeCodeCamp.
SSH Tips and Tricks by Carlos Alexandro Becker, including how to avoid having to touch Yubikey.
Do (not) Self-Host your repos by Kay Rhodes (@masukomi), explaining pros and cons of self hosting, with a simple suggestion on what to do.
The Git Commands I Use Every Day by Wade Zimmerman on DEV.to, originally published at devmap.org, a Medium blog.
Git Best Practices – How to Write Meaningful Commits, Effective Pull Requests, and Code Reviews by Grant Weatherston on freeCodeCamp.
Error: src refspec master does not match any – How to Fix in Git by Dillion Megida on freeCodeCamp.
Rewrite your git history in 4 friendly commands, making the git history of a demo project to start (again) with an “Initial commit”. By Salma Alam-Naylor on whitep4nth3r.com (also on DEV.to).
Fixing Some Bugs in My GitHub Profile Generator by Dave Rolsky on his House Absolute(ly Pointless) blog, among others on how to use linguist-generated gitattribute to exclude generated files from languages statistics.
Things I wish everyone knew about Git (Part I) and (Part II) by Mark Dominus (陶敏修) on The Universe of Discourse blog.
Why We Built an Open Source ML (Machine Learning) Model Registry with git by Dmitry Petrov of Iterative.AI (authors of DVC, CML and MLEM) on The New Stack.
- See Git-backed Machine Learning Model Registry to bring order to chaos, mentioned in Git Rev News Edition #89.
Git – Comparing Visual Studio 2022 with MeGit/EGit and SourceTree by Mark Pelf on CodeProject.
Kaleidoscope + Tower: the perfect Git setup by Florian Albrecht.
How we built Tower 3 for Windows by Kristian Lumme on Tower’s blog.
Mastering Google (for Developers) by Bruno Brito on Tower’s blog.
10 Useful Git Commands You Should Know by Bruno Brito on Tower’s blog.
Git Interview Questions - The essential list, including answers, a part of Git Tower’s Git FAQ (with tips for the Tower Git client).
Semantic Diff for SQL by Iaroslav Zeigerman; implementation discussed in this post is now a part of the SQLGlot library.

Git tools and sites

b4: has gained contributor oriented features, like b4 send to send patch series to a mailing list; see Konstantin Ryabitsev’s announce.
Gitsign: Keyless Git signing with Sigstore, with your own GitHub / OIDC (OpenID Connect) identity. Written in Go.
ghq provides a way to organize remote repository clones, like go get does; for example when cloning it makes a directory under a specific root directory. Written in Go.
Revup provides command-line tools that allow developers to iterate faster on parallel changes and reduce the overhead of creating and maintaining code reviews; it creates multiple independent chains of branches for you in the background and then creates and manages GitHub pull requests for all those branches. Written in Python.
git-of-theseus is a set of scripts to analyze how a Git repo grows over time.
- See The half-life of code & the ship of Theseus by Erik Bernhardsson (2016).
git_dash is a command-line shell script for generating a Git metrics dashboard directly in your terminal.
GitHub does dotfiles: Your unofficial guide to dotfiles on GitHub.

Credits

Git Rev News Edition 90 (August 31st, 2022)

chriscool — Wed, 31 Aug 2022 11:06:51 +0000

Git Rev News: Edition 90 (August 31st, 2022)

Welcome to the 90th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of July 2022.

Discussions

Reviews

[PATCH 0/2] git(1) doc + “git help”: split-out user & git format docs

Last October, Ævar Arnfjörð Bjarmason sent a patch series containing only 2 patches. The first one created a new “User-facing file formats” section in the main Git manual page by splitting it off from the existing “Guides” section. The reason for this was that it was a stretch to have manual pages like “gitignore(5)” in a section called “Guides” which otherwise contained pages like “gitcore-tutorial(7)”.

The second patch in the series created a new “Git file and wire formats” section in the main Git manual page. Contrary to the section created by the first patch, this one was only for internal file and wire formats, that users were not supposed to touch, like “gitformat-bundle(5)”.

The goal was to make the existing technical documentation, which was in “Documentation/technical/” and available only in the HTML format, more accessible and discoverable by moving it over into the new man page sections and adding the corresponding --user-formats and --git-formats option to the git help command.

The documentation had to be converted when moved over as the man page format was different from the previous technical documentation format, but the second patch only converted “bundle-format.txt” to a new “gitformat-bundle(5)” man page. The plan was to convert and move over more of them later.

Last December Ævar sent a version 2 of his patch series which now contained 5 patches instead of 2 and converted and moved over more documentation to the new man page sections.

The cover letter of this patch series contained the following examples of what the new git help options would show:
```
  $ git help --user-formats

  The user-facing file formats are:
     gitattributes          Defining attributes per path
     githooks               Hooks used by Git
     gitignore              Specifies intentionally untracked files to ignore
     gitmailmap             Map author/committer names and/or E-Mail addresses
     gitmodules             Defining submodule properties
     gitrepository-layout   Git Repository Layout

  $ git help --git-formats

  Git's internal file and network formats are:
     gitformat-bitmap                  The bitmap file format
     gitformat-bundle                  The bundle file format
     gitformat-chunk                   Chunk-based file formats
     gitformat-commit-graph            Git commit graph format
     gitformat-index                   Git index format
     gitformat-pack-protocol           How packs are transferred over-the-wire
     gitformat-protocol-capabilities   Protocol v0 and v1 capabilities
     gitformat-protocol-common         Things common to various protocols
     gitformat-protocol-v2             Git Wire Protocol, Version 2
     gitformat-signature               Git cryptographic signature formats
```
As well as for the first patch series, there was no comment on this patch series except for one from Eric Sunshine about a possible typo. Ævar replied to Eric agreeing to fix some wordings.

A version 3 of his patch series appeared only last July on the mailing list. Containing 7 patches, it converted and moved over even more documentation to the new man page sections.

Ævar soon spotted that gcc’s -fanalyzer option complained about some code in his patch series though. The issue was that the git help code, which was matching a user requested topic with a man page, assumed that the name of man page files started with “git” and then dropped this prefix. This was justified as all Git man page filenames have always started with “git”, but the -fanalyzer detected that things could go wrong if that was not the case.

So a few days later Ævar sent a version 4 of his patch series with only minor changes. One of them was fixing the -fanalyzer complaint by adding a new patch at the beginning of the series which would abort the current command using the BUG() macro in case the man page name didn’t start with “git”.

Junio Hamano, the Git maintainer, replied to Ævar suggesting a slightly different fix for the complaint. Junio also thought that “githooks(5)” didn’t really belong into a category named “user-formats”, as a hook can be written in any language, so there is no “format” for users to follow. Instead, he would have liked a better name for a category that could contain both “gitignore” and “githook” related pages.

Junio also suggested not distinguishing between <guide> and <doc> categories in the git help documentation, as at some point we would have enough <doc> documents that most probably everything not related to a specific command would become <doc>.

About the “user-formats” category name, Ævar replied that he couldn’t find a better word than “format”. He thought about “layout” as there is “gitrepository-layout(5)”, but found it odd.

He also proposed using <name> instead of <doc> or <guide> in the git help documentation. Junio replied that he preferred <doc> to <name> though.

Ævar and Junio also discussed interactions of the patch series with patches that were worked on by others at the same time.

A few days later Ævar then sent a version 5 of his patch series which mainly renamed “user formats” and “developer formats” to “user interfaces” and “developer interfaces”.

These changes allowed the new “user interfaces” section to also contain the “gitcli”, “gitrevisions” as well as “githook” man pages, while the “developer interfaces” had pages called “protocol-*” instead of only “format-*”:
```
  $ ./git help --user-interfaces
  User-facing repository, command and file interfaces:
     attributes          Defining attributes per path
     cli                 Git command-line interface and conventions
     hooks               Hooks used by Git
     ignore              Specifies intentionally untracked files to ignore
     mailmap             Map author/committer names and/or E-Mail addresses
     modules             Defining submodule properties
     repository-layout   Git Repository Layout
     revisions           Specifying revisions and ranges for Git

  $ ./git help --developer-interfaces
  File formats, protocols and other developer interfaces:
     format-bundle             The bundle file format
     format-chunk              Chunk-based file formats
     format-commit-graph       Git commit graph format
     format-index              Git index format
     format-multi-pack-index   The multi-pack-index file format
     format-pack               Git pack format
     format-pack-cruft         The cruft pack file format
     format-signature          Git cryptographic signature formats
     protocol-capabilities     Protocol v0 and v1 capabilities
     protocol-common           Things common to various protocols
     protocol-http             Git HTTP-based protocols
     protocol-pack             How packs are transferred over-the-wire
     protocol-v2               Git Wire Protocol, Version 2
```
Along with other small fixes in the git help documentation, the new version also didn’t distinguish between <guide> and <doc> categories anymore.

The only comment on this version was from Eric who found a trivial typo in a commit message.

Anyway a few days later Ævar sent a version 6 of his patch series fixing the trivial typo.

Junio commented that the first patch in this series, which had been added in version 4 of the patch series to fix the -fanalyzer complaint, wasn’t really needed. What wasn’t actually needed was the BUG() macro aborting everything in case the name of the man page didn’t start with “git”, as it could be an unnecessary roadblock if we ever wanted to add such man pages.

After some further discussion, Ævar sent a version 7 of his patch series.

This series mostly removed the BUG() macro that had been added previously, but in the first patch still refactored the code dropping the “git” prefix when a user requested topic needs to be matched with a man page.

Junio commented about this first patch that he wasn’t sure the commit message properly described what the code was doing in case the man page name started with something like “git-git”.

He then spotted an issue with how some changes were split into different patches, and suggested that a man page should be split into different pages for different topics, while two other man pages about similar topics should be merged into one. He also mentioned some “leftoverbits” that could be done later.

Ævar sent a version 8 of his patch series taking account Junio’s suggestions, except for one documentation page, which he decided to be converted later if needed, so he just removed the changes converting it from the patch series.

Junio reviewed the series again and liked what it was doing. He discussed further changes a bit with Ævar, but they agreed that they could be done later in another patch series.

Since then, version 8 of the patch series has been merged into the master branch, so we should have a significantly improved documentation and help system in the next Git feature release (v2.38.0) that should be out in the first weeks of October.

Developer Spotlight: Glen Choo

Who are you and what do you do?

I’m a Software Engineer at Google on a team that works on Git. My prior experience is comprised solely of different flavours of proprietary web apps, so I’m constantly grateful for the opportunity to work on the polar opposite of that :).

The only interesting thing I do outside of work is rock climbing. Sometimes, I wish I spent as much time rock climbing as I do working, which probably means that I should figure out how to do both simultaneously.
What would you name your most important contribution to Git?

Hm, I’ve only been contributing for a short while, so it’s hard for me to call any of them important per se. The most user-visible one is safe.bareRepository, but I don’t think many users will use it in its current form. If I had more time, I’d expand it into a safer default for everyone.
What are you doing on the Git project these days, and why?

Most of my work has been focused on getting submodules to work with branches as well as general submodule cleanup work. I get a kick out of searching “git submodule bad”, nodding my head at every single complaint and dreaming about the day I get accurate search results for “git submodule good”.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’d probably find a different way to structure the test suite so that we could share far less state between tests, or maybe come up with a way to visualize the setup for each test case. It would be nice to be able to read just a single test case to understand what’s happening.

If I had 5 teams of experts and 10 years I’d lib-ify all of Git’s internals and have the Git CLI call the Git library in the same way everyone else calls libgit2.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I’d remove nearly all of the CLI flags and replace them with more consistent, mnemonic flags. It’s fun to be able to throw Git CLI trivia at friends, but at some point, maybe it would be better for them to be able to remember it themselves.
What is your favorite Git-related tool/library, outside of Git itself?

I owe almost everything I know about Git to Magit (the Emacs plugin). When I was much much newer to Git, it was a safer, friendlier, more discoverable entry point than the Git CLI. These days, it’s still an essential part of my toolbox since it vastly reduces the number of keystrokes (I’m a really bad typist) and it gives an amazing interface for modifying and applying diffs (I still have not touched “git add -p” and at this point, I think it’s too late to start).

Honourable mention goes to git-branchless. It does so many amazing things that I’ve grown to rely on, like anonymous branches, obsolescence tracking, and history manipulation.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Jeff King, one of the most prolific contributors, took a break from the Git project last year. I was probably one of the first people to realise when he came back from the break because his first email on the mailing list was a bug report comment on a bug that I created :’).
Could you describe your Git development toolbox?

For reading email, I’ve configured an email folder for the mailing list, which gets pulled down by offlineimap + notmuch. I read email using notmuch-emacs, which claims to be a frontend to notmuch, but is actually also a full-fledged MUA (just like how Emacs claims to be a text editor, but is actually an OS).

For reviewing patches, I apply the patches to a dedicated worktree using b4. “b4 shazam” is as close to painless as I can imagine.

For sending patches, I wrote a bunch of scripts around “git format-patch” and “git send-email” and organised my branches so that I could keep track of each version I sent out. Then one day I tried GitGitGadget, realised that it does nearly all of those things for me for free, and those scripts have remained virtually unused since :). I will probably never use them again once GGG learns how to base topics on topics.
What is your advice for people who want to start Git development? Where and how should they start?

The best place to start is to get acquainted with the mailing list and the community. Reading the mailing list and sending a low-stakes patch (like a doc fix or usage string fix) are pretty good ways to do this. Folks on the mailing list tend to communicate in a distinctive style – it’s often direct, and silence can have a different meaning from what you’re used to. I’m guessing that for most people, learning how to communicate effectively on the mailing list is harder than the actual technical aspects of Git development.

I’d also recommend that newcomers fight the urge to make their v1 patches absolutely perfect. The community is pretty accommodating to new contributors, so once you’re convinced that the codebase is better off with your change than without, it’s fine to send it out! Far more often than not, it will lead to a positive interaction.
If there’s one tip you would like to share with other Git developers, what would it be?

Assume good intent from the people you interact with. I think the mailing list can be intimidating at times (especially to newcomers), but if you assume good intent, then everyone suddenly seems friendlier and feedback becomes easier to receive. And of course, remember to pay it forward by acting with good intent.

Releases

Git 2.37.2
Git for Windows 2.37.2(2), 2.37.2(1)
GitLab 15.3.1 15.3, 15.2.2
Bitbucket Server 8.3
GitHub Enterprise 3.5.4, 3.4.7, 3.3.12, 3.2.17
GitHub Desktop 3.0.6

Other News

Various

A series of posts about “Git’s database internals” by Derrick Stolee has been published on GitHub’s blog site:
- part 1 is about how Git stores object data,
- part 2 is about commit history queries,
- part 3 is about file history queries,
- part 4 is about distributed synchronization,
- part 5 is about scalability.
The full lineup for Git Merge 2022 has been revealed by Lee Reilly.

Git tools and sites

prr alias ‘Pull request review’ by Daniel Xu allows “offline reviews and inline comments” to Github PRs.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Glen Choo, Carlo Marcelo Arenas Belón and Johannes Schindelin.

Git Rev News Edition 89 (July 31st, 2022)

chriscool — Sun, 31 Jul 2022 11:06:51 +0000

Git Rev News: Edition 89 (July 31st, 2022)

Welcome to the 89th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of July 2022.

Discussions

Support

[BUG?] Major performance issue with some commands on our repo’s master branch

Tassilo Horn sent a long email to the mailing list saying that while writing the email he found a solution to his problem, and that he tells about that solution at the end of the email.

He then explained that he works on a quite big repo where usual commands were all quick, but some plumbing commands invoked by Magit were “extremely slow for no obvious reasons”.

He found that:

git show --no-patch --format="%h %s" "master^{commit}" --

took around 13 seconds, while:

git show --no-patch --format="%h %s" "SHD_ECORO_3_9_7^{commit}" --

took around 23 milliseconds.

So there was almost a factor of 1000 difference when the same command was launched on the master branch or on the last release branch.

He suspected that the difference could have something to do with the fact that there had been a lot of merges recently in master.

The solution he found while writing the email was to comment out the diff.renameLimit = 10000 he had in his ~/.gitconfig file. This reduced the time for the first command above from 13 seconds to 150 milliseconds.

Tassilo wondered though why diff.renameLimit had such an influence, as, when --no-patch is provided, no diff should be generated.

Tao Klerks replied to Tassilo that he used to use git show to get metadata from a big repo as the command allows specifying an arbitrary list of commits in one call which can save process overhead on Windows. He stopped using git show though after it had been reported to be slow. Instead he switched to git log and accepted some process overhead, as it solved his problem.

He found that large commits and merge commits with a number of changes on any side were slow despite using --no-patch. And Tassilo’s email made him suspect that it could be linked to rename detection.

Tassilo replied to Tao that using git log also solved his problem but that someone might want to do something to fix git show when no diff was generated.

Tao replied that he found that adding --diff-merges=off to the git show --no-patch ... command made it perform as fast as git log. So he could now combine the performance of git log with passing an arbitrary list of commits that git show allowed.

Peff, alias Jeff King, also replied to Tassilo that git show might in some cases need underlying diffs even if --no-patch is requested, while git log might need them too, but not when looking at merges. Peff wondered if the code could be changed to detect when underlying diffs aren’t needed, but thought that it could make the code “a bit brittle”.

Kyle Meyer then asked Peff if making --no-patch imply --diff-merges=off was safe, as Tao suggested, and showed benchmarks on the git.git repo where it was nearly 15 times faster with --diff-merges=off.

Peff replied that he wasn’t sure it would be safe and gave an example of a git show command using --diff-filter=D where the output changes when diff merges are suppressed as the commit isn’t showed then. He suggested a mode skipping the diff when it’s not shown but always showing the commit. He said that it would require someone verifying it does the right thing in all cases though.

Junio Hamano, the Git maintainer, chimed in to agree with Peff that making --no-patch imply --diff-merges=off would cause a regression, and mentioned other git show options where the output could be affected.

Junio also elaborated on Peff’s idea of a mode skipping the diff when it’s not shown but always showing the commit. He suggested an explicit git show --log-only option and mentioned a few ways to make it work regarding other options.

Peff and Junio discussed the idea a bit more, but it doesn’t look like something will be implemented soon.

Tassilo and Peff also discussed the diff.renameLimit option a bit. It looks like Tassilo would like to set it to a high value only in some contexts, though the current config might not be sufficient to express that.

Developer Spotlight: Junio C Hamano

Who are you and what do you do?

I am an open source toolsmith, who works at Open Source Program Office (OSPO) at Google. I work as the maintainer of Git.
How has your journey with Git as its maintainer been so far?

I have worked with many contributors since 2005, and seeing so many of them grow into excellent developers as they work on this project was a joy.
How does your work as the maintainer of the Git project look like?

Unlike earlier days, I no longer have to be in the driver’s seat to design or implement a big feature, and luckily there are multiple groups of people who do excellent job dreaming up new ways to use Git and make it a reality. My best days start by getting greeted by a surprisingly good proposal of a new feature or optimization of an existing feature, and the entire day is spent on reviewing them. It happens less often these days, but they still do occasionally.

On my normal days, I scan the mailing list for patches and discussions. My goal is to at least open every one of incoming messages, and read carefully at least half of the patches I pick up to queue on the ‘seen’ branch, which means that I may be queuing the other half without carefully reading, trusting the reviews already done by other members of the community.

I aim to finish picking up new topics, replacing existing topics, and generally interacting with the mailing list, by around 2pm. Then I rebuild the ‘seen’ topic, rewrite the latest draft of “What’s cooking” report (which is the guide to choose which topics will go to the ‘next’ branch), and push out the first integration result of the day by 4pm. After that, I merge the topics that have cooked long enough in ‘next’ to ‘master’, and the topics that have been adequately reviewed to ‘next’. The ‘seen’ and ‘next’ branches are rebuilt, the “What’s cooking” report is rewritten, and the second integration result of the day gets pushed out, before I call it a day.
If there’s anything you would like to say to your past self, what would that be?

Study math and algorithms harder, perhaps. I know them well enough to get around, but it is primarily because there are so many other community members who are good at them that I can rely on, so I do not have to get involved in details that are too deep for me.
What would you name your most important contribution to Git?

There are too many to list in the design and implementation of the internals, but in the end, I think what mattered to the project most was that I was consistently there, available to help guide the project.

While it may not be a particularly “important contribution”, my most favorite creation is git rerere. It was fun to design, work on, and (most importantly) name it.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

The interoperability between SHA-1 and SHA-256 repositories first comes to mind. The ingredients are almost all there, so are rough designs.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I generally think that the hacks to lie to the object layer, like “grafts” and “replace” mechanisms, and “alternate” object store, were not great ideas. There aren’t all that many that I would remove, but there are too many that I wish we could redo entirely without backward compatibility issues (e.g. path ordering in the index).
What is your favorite Git-related tool/library, outside of Git itself?

My recent favorites are Eric’s “public-inbox”, which powers the https://lore.kernel.org/git mailing list archive, and Konstantin’s “b4” that helps to interact with the lore archive better.
What is your advice for people who want to start Git development? Where and how should they start?

That depends on why they want to do so. Do they not like the way the tool currently works and they want to change it? Are they happy with Git but they feel they do not know enough of it and are curious about how things work? For the former folks, the usual “scratch your itch” advice would work well to a certain extent. For the latter folks, their “itch” can be to try to figure out how one of their favorite subcommand works, and then perhaps clean up or optimize the code paths they studied. Following what our test scripts are doing to your favorite feature may be a great way to learn them, too.

Either way, while identifying and scratching their “itch”, I’d recommend they lurk on the mailing list for at least a few weeks, and starting early is good. Learn by reading others’ patches being discussed, the kind of things the reviewers are interested in, and how the development process works. See who is active and how the discussion goes. These social conventions, how our developers work with others, are just as important as, if not more than, technical details. The “MyFirstContribution” document may also be a good place to start.
How does your mailing list workflow look like?

I try not to be the first to comment on any new topic (unless the topic gains no attention from anybody, yet it looks worth commenting on, which sometimes happens). This is because other members of the community may offer interesting viewpoints that I would not hear (and think of myself) if I spoke first.

My ideal is that a topic gets discussed without me for a few rounds and by the time I feel like taking a look myself, it is already quite ready, thanks to the help from competent reviewers (which happens quite often). Then I can pick it up and queue almost directly to ‘next’ (in practice, I’d first merge it to ‘seen’ to ensure that there is no funny interactions with existing topics in the first integration cycle of the day that happens before 2pm, and then merge it down to ‘next’ in the second integration cycle of the day, or perhaps the day after).

As I cannot keep track of all the things said in the discussion on all topics, I make heavy use of the lore archive and use the draft of “What’s cooking” report to take notes on each topic’s current status. So, the workflow is
1. to notice a new topic, whose merit is either obvious to see or others reviews helped to highlight, and queue it to ‘seen’, while sending comments to them,
2. record the topic in the “What’s cooking” draft,
3. to observe the discussion on the topic, perhaps taking a reroll and replacing the copy I have,
4. send out an updated “What’s cooking”, possibly the topic marked for promotion,
5. go back to (3)
until each topic graduates to ‘master’.
If there’s one tip you would like to share with other Git developers, what would it be?

It is very easy to be too strongly married to your initial solution and become blind to the merits of other approaches suggested in the discussion by others, or accept a possible reframing of the original problem to solve a wider problem.

In the very early days of Git, before Linus passed the project’s maintainership to me, I also had a “competitive” manner in a bad way. There were plenty of problems to be solved, and it felt as if people competed to be the first to offer a solution to each of them. When I had an idea to solve a problem that others were also interested in, sometimes it felt like I had to “beat” them, which meant that I had to send out patches even before they are well reasoned and well explained enough. Luckily, being maintainer means I no longer have to compete with others. Instead I can set the pace of the project. After having lived in such a “competitive” way for a few months and saw its downsides, I learned to give contributors time to think things through and wait for counter-proposals.

So, one “tip” is to take things slowly. Be ready to step back, take a deep breath and take time to rethink the problem, together with those in the discussion. You’d end up working well with the others that way.

Releases

Git 2.37.1 and others
Git for Windows 2.37.1(1)
libgit2 1.5.0, 1.4.4
GitHub Enterprise 3.6.0, 3.5.3, 3.4.6, 3.3.11, 3.2.16, 3.5.2, 3.4.5, 3.3.10, 3.2.15
GitLab 15.2.1, 15.1.4, and 15.0.5 15.2, 15.1.3, 15.1.2, 15.1.1
GitHub Desktop 3.0.5, 3.0.4
Sourcetree 4.1.9

Other News

Various

Contributor’s Summit Registration details have been posted by Taylor Blau. As usual the Summit will happen the day before the main conference day of the Git Merge and very close to it.
GitLive 15.0: Offline merge conflict detection across all branches for any Git repository and more by Agnieszka Stec.
Iterative.AI, authors of the DVC Data Version Control tool (first mentioned in Git Rev News Edition #42), bring Git-backed Machine Learning Model Registry to Iterative Studio.
About GIT Internals: Aman asked how to better understand GIT software internals. Junio (maintainer) suggested starting at the Initial revision of “git”, the information manager from hell (e83c5163, v0.99~954). “With only 1244 lines spread across 11 files, it is a short-read that is completable in a single sitting for those who are reasonably fluent in C. It does not have any frills, but the basic data structures to express the important concepts are already there.”
Matheus Tavares successfully defended his Master’s dissertation about parallelizing Git checkout. Some of his work on this was done during his 2019 Google Summer of Code.
Whatever happened to SHA-256 support in Git?: an article by Jonathan Corbet on LWN.net.
Give Up GitHub: The Time Has Come! by Denver Gingerich and Bradley M. Kuhn of Software Freedom Conservancy, (see also Open source body quits GitHub, urges you to do the same in The Register) calls for FOSS project to migrate away from GitHub.

Light reading

Introduction to Git Ops: Some useful background to the Git - DevOps approach in this sponsored article.
Git workflows: Best practices for GitOps deployments, describing differences between how you manage your code in Git and how you manage your GitOps configuration in Git. By Christian Hernandez, GitOps Advocate, on Red Hat Developer blog.
git rebase --fork-point considered harmful (by me): The reflog lookup heuristics aren’t what you thought, are they? A UX report by Josh Bleecher Snyder.
Git Delete Branch How-To, for Both Local and Remote with pictures, also includes deleting branches on GitHub.
Git - Subtree: A short overview of the common replacement for Git submodule.
Managing Git projects with submodules and subtrees (2020): More choices. This was previously mentioned in Git Rev News Edition #63.
‘Turn off merge fast-forward by default’: An alternative viewpoint (from Git for Windows #3858) by Maciej Radzikowski on the Better Dev blog.
Getting Started with Git Hooks and Husky by Bruno Brito on Tower’s blog.
“Codeberg” series by Flavio Poletti (@polettix), starting with Codeberg and currently ending with Codeberg Pages - Custom domains, describes the Codeberg hosting service, which is powered by Gitea software (a fork of Gogs, which is written in Go).
Write Better Commits, Build Better Projects: Learn strategies to improve and use commits to streamline your development process. By Victoria Dye on GitHub Engineering Blog.
Write Git Commit Messages That Your Colleagues Will Love by Simon Egersand on DEV.to.
Why I love Tig for visualizing my Git workflows by Sumantro Mukherjee (Correspondent, Red Hat) on OpenSource.com.

Easy watching

Git Internals - The BLOB: ‘A shot of code’ looks at the internals of the .git folder to see exactly what goes on under the hood.
Getting Comfortable with GIT, looking to get a deeper understanding of Git, and hopefully feeling a lot more comfortable when performing some of the more scary Git operations… says ‘A shot of code’.
It’s Impossible to Know If You’re a Good Programmer: The impostor syndrome and irrelevant code challenges.

Git tools and sites

Git Signing: All the details for signing commits and tags (for non-repudiation) in GitHub using GPG, Vault, Yubikey, Keybase!
Git-Story: Animate the story of your Git project, by creating video animations (.mp4) of your commit history directly from your Git repo. Note: arrows point in the direction of increasing time, not from commit to its parents.
- See also How to Animate Your Git Commit History with git-story by Jacob Stopak on freeCodeCamp.
GitHub Actions Kotlin DSL (docs) allows authoring GitHub Actions workflows for GitOps in Kotlin.
- See also GitHub Actions DSL: a New Hope in YAML Programming Wasteland by Jean-Michel Fayard on DEV.to.
jc (JSON Convert) is a CLI tool and Python library that converts the output of popular command-line tools and file-types to JSON, YAML, etc… including git log. This allows automated processing with tools such as jq, and simplifying automation scripts.
GitJournal is a mobile first Markdown notes app integrated with Git, for Android and iOS, that can work with any Git hosting provider (via SSH).
data-diff is an open-source command-line tool and Python library by Datafold to efficiently diff rows across two different databases.
- See also references to various blog posts by Tim Sehn on DoltHub Blog about version control, Git, and databases, which appeared in Git Rev News Edition #82.
GitHacker is a multithreaded tool to detect whether a site has the .git/ folder leakage vulnerability, and if so restores the entire Git repository, including data from stash.
- See also Please remove that .git folder from directory browsing on the web server to avoid information leaks. Don’t deploy the .git/ folder or, at least, forbid access. By Julien Maury (jmau111) on DEV.to and on his own blog.
Build your own X is a compilation of well-written, step-by-step guides for re-creating our favorite technologies from scratch, including Build your own Git.

What I cannot create, I do not understand — Richard Feynman.

Credits

Git Rev News Edition 88 (June 30th, 2022)

chriscool — Thu, 30 Jun 2022 11:06:51 +0000

Git Rev News: Edition 88 (June 30th, 2022)

Welcome to the 88th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of May and June 2022.

Discussions

General

Google Summer of Code contributors working on Git are now in the “Coding Period” (from June 13 to September 19) of the program and have posted at least once on their blogs:
- Abhradeep Chakraborty, who works on “Reachability bitmap improvements”, has published his latest post on his Medium blog.
- Shaoxuan Yuan, who works on “More Sparse Index Integrations” has published his latest post on his website.
- Jaydeep Das, who works on “Unify ref-filters with other pretty formats” has published his latest post on his website.

Support

Bug in merge-ort (rename detection can have collisions?)

Glen Choo reported on the mailing list that git merge was failing on certain branches of a repo used at his workplace. As the repo is a public one, Glen was able to share the full recipe to reproduce the bug.

When following it, this error appears:

Assertion failed: (ci->filemask == 2 || ci->filemask == 4), function apply_directory_rename_modifications, file merge-ort.c, line 2410.

Glen noticed that the bug seemed to be specific to the “ort” merge strategy, which became the default merge strategy in Git 2.34.0 released last November. When using the “recursive” strategy, which used to be the default merge strategy before “ort” took over, the merge seemed to work as expected.

Glen also tried to debug the issue by himself and found that the reason for the assertion failure seemed to be that two files involved in the merge were renames of each other.

Elijah Newren, who developed the new “ort” strategy, thanked Glen for the detailed report, and said that he found a small reproduction recipe to simplify what’s going on. He explained it with the following sequence:

#   Commit O: sub1/file,                 sub2/other
#   Commit A: sub3/file,                 sub2/{other, new_add_add_file_1}
#   Commit B: sub1/{file, newfile}, sub1/sub2/{other, new_add_add_file_2}
#
#   In words:
#     A: sub1/ -> sub3/, add sub2/new_add_add_file_1
#     B: sub2/ -> sub1/sub2, add sub1/newfile, add sub1/sub2/new_add_add_file_2

He noted, though, that he can also trigger a different fatal error in the “ort” strategy with a small tweak to the test setup, and can also trigger that same other fatal error in the “recursive” strategy with his test cases.

He then explained that both the “ort” and “recursive” merge strategies have code to avoid “doubly transitive [directory] renames”. Such renames happen when, for example, on one side of the merge a directory named “A” is renamed to “B”, while on the other side “B” is renamed to “C”.

However, the code to avoid “doubly transitive [directory] renames” is fooled when a parent directory of a directory is renamed. For example if on one side a directory named “A” is renamed to “B”, while on the other side a leading directory of “B” is renamed to “C”. That still wouldn’t be quite enough to trigger this bug, though. It also requires adding a file into directory A on one side and a file with the same name into directory B on the other.

Junio Hamano, the Git maintainer, thanked Elijah for his continued support of the merge strategy, and noticed that at least the code was not “making a silent mismerge” in this special case, and that the recursive strategy could be used as a fallback.

Elijah replied that he was glad the recursive strategy worked for Glen but noted that it didn’t work with his minimal reproduction test case, which suggests it’s less reliable as a fallback than one might hope.

Glen then wondered if turning off rename detection could help in case of merges with complex renames like this, but Elijah pointed out that might be more problematic than helpful, particularly since this case had a very large number of renames and users tend to have difficulty correctly resolving the conflicts that result from a lack of rename detection. However, he suggested that if turning off rename detection was really wanted that one could use the “resolve” strategy instead, which “is roughly the recursive strategy minus the renames and the multiple merge base handling”.

Elijah also posted a small patch series that adds test cases demonstrating the bug Glen found and the related ones he found based on it, and fixes the bugs in the ort strategy. (The recursive strategy is deprecated, and the bugs noted here are not security critical.)

Jonathan Tan reviewed the series and verified that it indeed fixes Glen’s test case. Calvin Wan also commented on the patch series. So there is good hope that after a few iterations to polish the series the bugs will be fixed soon.

Releases

Git 2.37.0, 2.37.0-rc2, 2.37.0-rc1, 2.37.0-rc0
Git for Windows 2.37.0(1), 2.37.0-rc2(1), 2.37.0-rc1(1), 2.37.0-rc0(1)
Bitbucket Server 8.2
Gerrit Code Review 3.6.1
GitHub Enterprise 3.5.1, 3.4.4, 3.3.9, 3.2.14, 3.1.22
GitLab 15.1 15.0.3, 15.0.2, 15.0.1, 14.10.4, and 14.9.5
GitHub Desktop 3.0.3, 3.0.2, 3.0.1
Tower for Mac 8.3
Tower for Windows 3.3

Other News

Events

Git Merge 2022 by Lee Reilly on GitHub blog. Git Merge, the conference dedicated to bringing the Git community together, returns on September 14-15 in Chicago, Illinois, USA. Call for Speakers is open through Sunday, July 10.

Various

Highlights from Git 2.37 by Taylor Blau on GitHub’s blog.
v2.37.0 highlights video by GitKraken.
How Atlassian made Git push over HTTPS faster for Bitbucket Cloud by Brent Thew on Atlassian Engineering blog.
Why We’re Sticking with Ruby on Rails at GitLab by Sid Sijbrandij on The New Stack (contributed post, sponsored by GitLab).
Improved verification of historic Git commit signatures [in GitHub] with respect to public GPG signing keys that are expired or revoked (but not compromised).
AppSmith Adds Git Support to Low-Code App Dev Framework by Mike Vizard on DevOps.com.
Improve Git monorepo performance with a file system monitor by Jeff Hostetler on GitHub’s blog.

Light reading

Improvements in git 2.37 when resolving conflicts with vimdiff describes a change in Git 2.37 w.r.t. vimdiff mergetool drivers.
Better File Comparison with Kaleidoscope by Bruno Brito on Tower’s blog.
Working with Feature Branches by Bruno Brito on Tower’s blog.
Coming Up on Tower’s Roadmap by Bruno Brito on Tower’s blog.
The Three Phases of Software Development by Kristian Lumme on Tower’s blog.
Best practices for Git branching, describing Git flow at Halodoc, by Ashish Anand.
How to Recover a Deleted File in Git – Revert Changes After a Hard Reset by Zaira Hira on freeCodeCamp.
Git List Remote Branches by Quincy Larson on freeCodeCamp.
Replacing Your Git Command Cheat Sheet With AI Command Search by Jessica Wang on Warp blog; uses Warp’s AI Command search.
We Put Half a Million files in One git (Mono-)Repository, Here’s What We Learned by Ahn Lee in Canva Engineering Blog (a Medium-based blog).
- See also, for example, articles on Developer Homepage of Derrick Stolee, including The Future of Git at Scale 2021 presentation (slides available), a survey of some advanced Git features to help Git scale to the largest monorepos.
Reducing the size of a git repository with git-replace by Andrew Lock on andrewlock.net, where repository is split into a small “current” repository containing a minimal amount of history, and a “history” repository containing all the commits prior to the creation of the new repository, stitched together when needed with git-replace.
How to Prevent Merge Conflicts (or at least have less of them) by Rizèl Scarlett, featured on daily.dev (also on DEV.to). It is the last part of 3 part Intro to Git series on DEV.to, beginning with How Do I Resolve Merge Conflicts?.
People rarely use complicated git commands on the weekend, and I have the data to prove it. by Ben Halpern for The DEV Team on DEV.to.
How Git truly works by Alberto Prospero in Towards Data Science (a Medium-based blog).
Sourceware – GNU Toolchain Infrastructure roadmap by Mark J. Wielaard

Git tools and sites

Sourceware is community run infrastructure, mailing lists, git, bug trackers, wikis, etc. hosted in the Red Hat Open Source Community Infrastructure Community Cage. Uses shared buildbot for (test) automation, and patchwork for tracking the state of contributions; most tests upload all results to bunsendb. Uses mirror at SourceHut, https://sr.ht/~sourceware/, for web forge.
unix-history-repo is a repository representing a reconstructed version of the Unix history from 1970 until today, based on the currently available data. Note that this repository will be often automatically regenerated from scratch.
git-repair can repair various forms of damage to Git repositories; a complement to git fsck, which finds problems, but does not fix them. It is a Haskell program, developed as a spinoff of git-annex (for large files management).
Rich Enhanced Shell History (resh) provides contextual shell history for zsh and bash, where relevant results are based on current directory, git repo, exit status, and host.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Bruno Brito, Elijah Newren, Matheus Tavares and Johannes Schindelin.

Git Rev News Edition 87 (May 26th, 2022)

chriscool — Thu, 26 May 2022 11:06:51 +0000

Git Rev News: Edition 87 (May 26th, 2022)

Welcome to the 87th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the months of April and May 2022.

Discussions

General

Git participates in GSoC (Google Summer of Code) 2022

The following three contributors have been officially accepted to work on Git as part of the GSoC 2022:
- Abhradeep Chakraborty will work on the Reachability bitmap improvements project. He will be co-mentored by Kaartic Sivaraam and Taylor Blau.
- Shaoxuan Yuan will work on the More Sparse Index Integrations project. He will be co-mentored by Derrick Stolee and Victoria Dye.
- Jaydeep Das will work on the Unify ref-filters with other pretty formats project. He will be co-mentored by Hariom Verma and Christian Couder. His first blog post about it is up.
Congratulations to the selected contributors!

Thanks also to the other contributors who applied and worked on micro-projects, but couldn’t be selected! We hope to continue to see you in the community!
[ANNOUNCE] git-scm.com Heroku credits update

Taylor Blau announced that the Heroku credits for git-scm.com, Git project’s de facto homepage, would not be provided for free by Heroku anymore.

The Git project has so far relied on those free credits from Heroku and free support from Cloudflare to have $0 maintenance cost for the site.

Taylor suggested different options to deal with the change:
- convert to a static site, so that we don’t rely on Heroku and can be hosted elsewhere hopefully for free,
- try to reduce our Heroku bill by getting rid of some of the services we currently use (like database and Ruby on Rails cache),
- find a cheaper Ruby on Rails host.
The Heroku credits amount to around $132 per month that are now billed to Git’s account at Conservancy, as Git is Conservancy member, while we “figure out what to do next”.

A few days later, Taylor replied to himself saying that Dan Moore from FusionAuth has offered to help assist with our hosting costs, as FusionAuth, his company, “has benefited tremendously from Git”.

Git project funds are usually used for things like sponsoring travel and lodging for Git Merge attendees who could not otherwise make it in person, so helping for hosting costs is welcome.

Sponsors for the site are listed on the Sponsors section of the about page, so we would just have to list FusionAuth there along with Cloudflare and Bonsai.

Dan then replied to Taylor confirming that FusionAuth “would love to offer [their] monetary support if it makes sense for the community”.

Both Kaartic Sivaraam and Phillip Wood thanked Dan and his company for their offer, and agreed with Taylor that it would be a good solution.

Johannes Schindelin, alias Dscho, also replied to Taylor saying he would be in favor of converting the site to a static web site. Taylor then replied to Dscho, explaining some tasks, along with technical details, that would need to be taken care of for the conversion.

Junio Hamano, Taylor and Christian Couder also discussed the idea of proposing such conversion tasks as a future Outreachy or GSoC project.

For now the Git project accepted FusionAuth’s generous offer, and the git-scm.com web site will continue to run in the same way.

Developer Spotlight: Carlo Marcelo Arenas Belón

Who are you and what do you do?

I am a Peruvian hacker who likes to argue he is also “American” to his neighbours and accidental coworkers/friends in the USA, because while I flew to get here, and I even crossed an ocean to do so, I might as well have walked instead.

To be honest, my close family and probably most of my friends in Perú would instead call me a “characato” but I am starting to worry I am getting slightly off-topic here.

About “what I do”, it is a little complicated; I used to call myself a “server babysitter” until I had a real human one and realized how inaccurate that was. I usually have a lot of computers around me and one day realized I might become a cyborg of sorts even if none of them is strictly connected to me, because AFAIK nobody has figured out how to do that yet, but again I seem to be going off-topic, because I am guessing what you really meant is either “what it says in my current business card” or “what sort of thing I do to contribute to society that is good enough so I have the means to pay the bills”?

Well; due to either a series of unfortunate misunderstandings or some bureaucratic mistake akin to the Vogon Constructor Fleet job that demolished Earth at the beginning of the Hitchhiker’s Guide to the Galaxy, I am now open to a lot more opportunities to help you do anything, and MUST do it for free. Hope that is a good answer, but ping me if you would like some additional explanation.
What would you name your most important contribution to Git?

None.

I did break Git for macOS once long ago when I was trying to make it more useful in Linux. Then, I did the same at least once for Windows after I bought an Apple computer to make sure that wouldn’t happen again and changed my email address so no one would be able to connect the dots.

I might have found one bug in Windows that might have redeemed me from that breakage after I bought a Windows computer for similar reasons though.

I did fix Git for Minix after I met Linus Torvalds in a Google conference and just in spite of him not understanding a funny joke I made (not a fault of his, I am sure, since I have such a thick accent I sometimes can’t understand myself), but I had yet to upstream the patches, so maybe that?

Either way, I am hoping whatever it is, it will be great and might make my mom or my son proud, even if it is yet to come.
What are you doing on the Git project these days, and why?

Scratching itches and learning from the best, aren’t you?
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’m not sure if it will take a full year, but it would be great to have a Git conference to get everyone in a room (obviously not while there is a pandemic, of course).

Something less ambitious but maybe even more effective would be to get a virtual hackathon, even though I have to admit realistically a physical one would be even better.

It is a shame they don’t do the “Linux cruise” anymore, but it might be also a good format at a much smaller scale and I even remember reading somewhere that even in a cruise (which usually has terrible internet connectivity), Git was still useful since you might as well send patches around in USB drives.

I guess the first thing to implement in that hackathon might be ZMODEM transport for git push/pull, and I might be more than happy to make sure everyone has a working cable to use if they are still lucky enough to get a computer that has a DB9.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The bugs, but then even those are fun to have from time to time.
What is your favorite Git-related tool/library, outside of Git itself?

I don’t have a favorite, but it is because I just don’t know enough to have one. Luckily you guys have this monthly “magazine” of sorts, so I might be able to eventually find one.

It sort of feels as exciting as when I used to go to one private library in my hometown to read about the latest games in the computer magazines they had that I might be able to type into that first computer my parents got for me, that had an 8-bit CPU and 64KB of RAM (not all of it totally usable though, as it also had a ROM with a basic interpreter that I think used half of that), but I am not sure.
Do you happen to have any memorable experience w.r.t. contributing to the Git project? If yes, could you share it with us?

Lots indeed, that is why I sometimes actively try to fix some bugs any reasonable person would either ignore or at most report.

My code might be a mess, but I think it is usually better than a bug, and I get the chance to get to work and learn from people that are way better than me at fixing them, mostly nicer as well, and especially way more patient than I would be.
How does your mailing list workflow look like?

What do you mean by workflow?

(Editor’s note: Here, Carlo jokes about his workflow which according to him “is a nightmare that is stitched together with masking tape”.)
What is your advice for people who want to start Git development? Where and how should they start?

My first contribution was probably a real and annoying bug that I couldn’t believe was there, so most people I presume would just scratch that itch and go away.

Some might fall in love with the technology, or the community and come back like I did.

Regardless of that, there is a lot of wisdom (and luckily for me, incomplete features or minor bugs) which once you realize this tool is meant to be used by developers, kind of makes sense.

The documentation and the list content is pure gold, so take your time to read as much of it as you can first, if possible.

Jump straight at it and make sure all the tests and linters are quiet and try to fight the urge to send it out until you can’t improve it further and let it go.

Read the feedback you’d get, and try to improve it further based on that, and iterate. Be patient and take your time.
If there’s one tip you would like to share with other Git developers, what would it be?

Don’t Panic.

Releases

Git 2.36.1
Git for Windows 2.36.1(1)
GitLab 15.0 14.10.3, 14.10.2, 14.10.1, 14.9.4, and 14.8.6
Gerrit Code Review 3.3.11, 3.4.5, 3.5.2 and 3.6.0
GitHub Enterprise 3.5.0, 3.4.3, 3.3.8, 3.2.13, 3.1.21
GitKraken 8.5.0
Tower for Windows 3.2

Other News

Light reading

An overview of version control in programming by Daniel Lemire on his blog.
Revisiting the Pain: The World without Git by Sneh Chauhan for Kubernetes Community Days Chennai on DEV.to.
- Compare The Git Parable, by Tom Preston-Werner (2009) - the ideas behind the architecture of Git; covered in Git Rev News #30.
Mastering Tower (Mac Edition) by Bruno Brito on Tower’s blog.
Mastering Tower for Mac — 40 Tips in under 10 Minutes video by Bruno Brito.
Git Commit Message Template in Terminal and VS Code by Abbey Perini on DEV.to. This article refers to:
- How to Write a Git Commit Message (2014), which appeared in Git Rev News Edition #24.
- Conventional Commits specification, first appearing in Git Rev News Edition #52.
A Guide to writing Industry Standard Git Commit Message by Tuasegun on DEV.to.
Your Git Commit History Should Read Like a History Book. Here’s How. by Mirco, on Better Programming, a Medium blog (member-only story).
Automatically formatting and cleaning code on commit by Muhammad Sibra on Halodoc.
- This article mentions husky, which was first included in Git Rev News #63, and lint-staged, first mentioned in Git Rev News #45.
Squash [merge] commits considered harmful by Manuel Odendahl on DEV.to.
Can You Resolve Merge Conflicts Before They Happen? by Benjamin C. Baker on DEV.to describes how to resolve merge conflicts manually, and how one can detect potential conflicts in advance with the GitLive extension. GitLive was mentioned in Git Rev News Edition #77 and #82.
How to Resolve Merge Conflicts in Git – A Practical Guide with Examples by Tapas Adhikary on freeCodeCamp.
Arduino and Git: Two Views by Al Williams on Hackaday.
Why SQLite Does Not Use Git but Fossil (a version control system that was specifically designed and written to support SQLite). An article about Fossil did appear in Git Rev News Edition #11, but is nowadays unavailable except through the Internet Archive.
Rename rebase with git (2020), or how to perform a git rebase in which you rename a file without conflicts – though nowadays one would use git filter-repo instead of git filter-branch as in the article. Post on Andraž Bajt’s blog.
Repairing a corrupt Git repo using a clone (2016) on Andraž Bajt’s blog.

Git tools and sites

Commit Message Editor plugin for Visual Studio Code, by Adam Bender. The default settings follow the Conventional Commits specification.
VSCode Git Commit Message plugin for Visual Studio Code, by Kévin Riouk. An extension made to formalize git commit messages.
Mergify is a web service for automatizing pull requests and securing the code merge using a merge queue. Free for open-source.
- Merging Pull Requests Like a Pro With Mergify by Aniket Pal on DEV.to.
Mani is a CLI tool that helps you manage multiple repositories.
- mani, a CLI Tool to Manage Multiple Repositories by Samir Alajmovic on DEV.to. The article includes list of alternatives.
Fig adds IDE-style autocomplete (including for git, cd, ssh) to your existing terminal (macOS Terminal, iTerm, Hyper, Tabby, Kitty, bash, zsh, …).
JSON Patch is a format for describing changes to a JSON document as a JSON document itself. Specified in RFC 6902.
sqldiff.exe is a command-line utility program (Windows binary) that displays content differences between two SQLite databases.
Gitcoin (GTC) is a Web3 platform which combines open-source programming projects with an Ethereum-based crypto payment system. In spite of its name it has no connection with Git.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Carlo Marcelo Arenas Belón, Bruno Brito and Luca Milanesio.

Git Rev News Edition 86 (April 30th, 2022)

chriscool — Sat, 30 Apr 2022 11:06:51 +0000

Git Rev News: Edition 86 (April 30th, 2022)

Welcome to the 86th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of March 2022.

Discussions

Reviews

[PATCH 0/5] Separate --skip-refresh from --quiet in reset, use --quiet internally in stash

Victoria Dye sent a 5 patch long series to improve the following:
- the way the --quiet command line options work in git reset,
- the way index refreshing is handled in git reset, and
- the way the --quiet and --index command line option work in git stash.
She had discovered issues with these features when she was working on tests for the git stash sparse index integration. (See Victoria’s interview in last month’s Git Rev News Edition #85 for information on Victoria’s current work.) She found that --quiet in git stash does not suppress all non-error output when used with --index, and that this comes from reset_head() being called without the internal flag corresponding to --quiet.

When calling reset_head() with the flag set though, the index is not refreshed, while git stash needs the index to be refreshed. The underlying issue was that the internal flags related to --quiet and refreshing the index were not independent.

So the first goal with her patch series was to decouple these behaviors, and the second goal was to allow git stash to internally use reset_head() with the internal flag corresponding to --quiet and to still refresh the index.

To decouple the behaviors one of her patches introduced the --[no-]refresh option and the corresponding reset.refresh config setting to git reset. Derrick Stolee, who prefers to be called just Stolee, reviewed the patch series and agreed that the changes in that patch were “well motivated”, and otherwise he found that the “code looks great”, and he mostly suggested improvements to the tests.

Junio Hamano, the Git maintainer, also agreed that it was a good idea to separate refreshing from --quiet.

Victoria then sent a version 2 of her patch series, with improvements to the tests, some commit messages and the cover letter title.

Junio then reviewed the patch series and mostly suggested further improvements to the tests saying that otherwise “everything looked good”, while Stolee was happy with the series as it took into account all his previous suggestions.

Victoria then sent a version 3 of her patch series that added a few more tests and improved some others.

Junio and Victoria then discussed the tests a bit more, and Junio agreed with Victoria’s approach.

Phillip Wood though chimed in a few days later saying that the approach taken by the patch series, which consisted in still not refreshing the index by default when --quiet was given, was maybe not the best. He considered that it was a “hack” that had been introduced for performance reasons before the sparse index feature was introduced, and that we should take the opportunity to get rid of it and go back to the original behavior of refreshing the index when --quiet was given.

Junio agreed with Phillip saying that “he would very much prefer to see --quiet not making a contribution to the decision to refresh or not in the longer term”. He suggested introducing --no-refresh to git reset and said he thought reset.refresh wasn’t a good idea as it could lead to issues for people using git reset in scripts.

Victoria replied that she agreed with them but wanted to preserve as much backward compatibility as possible. She said she would gladly make the change if backwards-compatibility wasn’t an issue. She also asked if reset.quiet should be kept as it could also harm people using git reset in scripts.

As her patch series had already been merged into the next branch, she would send a new series on top deprecating reset.refresh and reset.quiet, and making refreshing the default for all modes of git reset.

Later she indeed sent the first version of a 4 patch long series removing all instances of skipping index refresh in git reset except for --no-refresh itself, and removing both reset.refresh and reset.quiet.

Phillip reviewed her new patch series suggesting to allow both --no-refresh and --refresh as one patch of the series removed the latter. He said that --refresh could be used to countermand a previous --no-refresh typically when using an alias that includes --no-refresh. He also discussed possible improvements to the documentation of --refresh and to commit messages.

Victoria then sent a version 2 of this new patch series taking into account Phillip’s suggestions.

Junio liked the changes and agreed to merge the series. Later though, Phillip suggested that the short help sentence given by git reset -h should be about --no-refresh instead of --refresh as this was “the form that users will want most of the time”.

Junio agreed with Phillip’s suggestion. He had already merged the series to next though, so he proposed another patch on top implementing Phillip’s suggestion. Victoria tested the patch and agreed with it. Junio replied he would merge it then.

All these patches were indeed merged into the master branch before the recent release of the latest Git 2.36.0, so that in this new Git version git reset and git stash handle some of their options in a much better way.

Releases

Git 2.36.0, 2.35.3 and below as a usability fix, 2.36.0-rc2, 2.35.2 and below for CVE-2022-24765 and CVE-2022-24767, 2.36.0-rc1, 2.36.0-rc0
Git for Windows 2.36.0(1), 2.36.0-rc2(1), 2.36.0-rc1(1), 2.36.0-rc0(1), 2.35.3(1), 2.35.2(1)
libgit2 1.4.3
GitHub Enterprise 3.4.2, 3.3.7, 3.2.12, 3.1.20, 3.4.1, 3.3.6, 3.2.11, 3.1.19
GitLab 14.10 14.9.3, 14.6.7, 14.9.2, 14.8.5, and 14.7.7
GitKraken 8.4.0
GitHub Desktop 3.0.0, 2.9.15, 2.9.14, 2.9.13

Other News

Various

Git security vulnerability announced by Taylor Blau.
- The risks of embedded bare repositories in Git by Jake Edge on LWN (free link for non-subscribers).
Highlights from Git 2.36 by Taylor Blau.
Public open source projects are eligible for Ultimate [GitLab] tier features by Orit Golowinski on GitLab blog.
GitHub can now auto-block commits containing API keys, auth tokens by Sergiu Gatlan.

April Fool’s

Make a cup of coffee with Git by Moshe Zadka on opensource.com.
Announcing git snail-mail on Drew DeVault’s blog… which almost got created for real (though without git scan-mail it would require).

Light reading

Securing Developer Tools: Git Integrations by Thomas Chauchefoin on SonarSource blog.
Mac Dev Survey 2022 Results by Kristian Lumme on Tower’s blog.
Setting Up Git on Windows Subsystem for Linux by Bruno Brito on Tower’s blog.
How to Clean Up Fully Merged Feature Branches by Bruno Brito on Tower’s blog.
How to Use the Git Stash Command by Preethi on freeCodeCamp.
Git Credential Manager: authentication for everyone by Matthew John Cheetham on GitHub blog, in Engineering.
The friend zone: friendly forks 101 by Lessley Dennington on GitHub blog, in Engineering and Open Source.
Handling messy pull-request diffstats by Jonathan Corbet on LWN (free link for non-subscribers).
- Present in the Linux kernel documentation as maintainer/messy-diffstat.rst.
Radicle: a Decentralized Alternative to GitHub for Web3 by Jake Ludington on The New Stack. Radicle was previously mentioned in Git Rev News Edition #49 and #70.
Explaining Git branches with a LEGO analogy by Seth Kenlon on opensource.com.
Make your own Git subcommands by Seth Kenlon on opensource.com.
How I use the Git for-each-ref command for DevOps by Evan “Hippy” Slatis on opensource.com.
My guide to understanding Git rebase -i by Vaishnavi R on opensource.com.
How to “Undo” Pushed Commits with Git by Rizèl Scarlett for GitHub on DEV.
5 resources to get your Monorepo off the ground by Matti Bar-Zeev on DEV;
- first mention of monorepos in Git Rev News can be found in edition #4,
- most recent mention is the Monorepo.tools site in edition #84.
Use Git tactically: How you can use micro-commits to effectively apply the Strangler Fig pattern, by Mark Seeman on The Overflow (Stack Overflow blog).
The Programmer’s Brain by Felienne Hermans: Why we should be taught to ‘read code’.
Working on two git branches at once with git worktree by Andrew Lock on andrewlock.net.

Git tools and sites

Building Software Together is a free online book by Greg Wilson which aims to teach you how to be a compassionate programmer; it includes two chapters about Git:
- Chapter 7: Using Git On Your Own
- Chapter 8: Using Git Together
Version Control with Git is a tutorial by the Software Carpentry Foundation.
git-backup is a command-line tool to pull all your GitHub and GitLab repositories for backup purposes; it doesn’t require Git.
gitquickbranch.c by Dianne Skoll is a small program in C to quickly find the current branch name.
delta is a syntax-highlighting pager for git, diff, and grep output.
- It is one of the tools on Modern Unix tools list, which is a collection of modern/faster/saner alternatives to common unix commands.
Difftastic is an experimental diff tool that compares files based on their syntax. The manual includes list of some other tree diffing tools available.
Vershd is an Electron-based multi-platform Git GUI, with separate views of branches and their commits, pending files and stashes, and the ability to show in advance what’s going to happen when actions are taken. Free for, among others, personal use and educational institutions. If only it’s marketing was less FUD-ish (“Git […] can easily destroy days of work in just seconds and requires thousands of keyboard commands and parameters”)…
Git for Professionals – Free Version Control Course: freeCodeCamp intro by Tobias Günther with follow-on more ‘Advanced Git Tutorial’ sessions, all on YouTube. Plenty of useful tidbits.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Bruno Brito, Brandon Pugh, Carlo Marcelo Arenas Belón and Philip Oakley.

Git Rev News Edition 85 (March 31st, 2022)

chriscool — Thu, 31 Mar 2022 11:06:51 +0000

Git Rev News: Edition 85 (March 31st, 2022)

Welcome to the 85th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of February 2022.

Discussions

Reviews

[PATCH] http API: fix dangling pointer issue noted by GCC 12.0

Ævar Arnfjörð Bjarmason sent a patch to the mailing list to fix an issue that appears when compiling Git with the gcc 12.0 development branch.

The issue is that this gcc version emits a warning on the last line of the following code:
```
      int finished = 0;

      slot->finished = &finished;
```
where slot is an instance of struct active_request_slot which has an int *finished member.

The warning is “storing the address of local variable ‘finished’ in ‘*slot.finished’ [-Werror=dangling-pointer=]”.

Ævar first thought about making the struct active_request_slot member an int finished member, so it wouldn’t be a pointer anymore, and then about removing the int *finished member entirely and using the int in_use member instead. His patch implemented the latter.

Taylor Blau reviewed Ævar’s patch but wasn’t sure about one of the places where the int *finished member was removed.

Junio Hamano also reviewed the patch and wondered if the new gcc version was correct in flagging the code in the first place, as it appeared that slot->finished wasn’t used outside the function where it’s assigned the address of a local variable.

Junio also wondered if it was correct to remove the int *finished member entirely and use the int in_use member instead, as that looked like reversing the patch that introduced int *finished without fully explaining why it was correct to do so.

To address the issue Junio then proposed implementing the following:
```
      if (slot->finished == &finished)
            slot->finished = NULL;
```
so that hopefully gcc would understand that the slot->finished field isn’t using a local address outside the current function.

Ævar replied to Junio, that assigning slot->finished to NULL at the end of the function would indeed quiet gcc. So he sent a version 2 of his patch that only added slot->finished = NULL; at the end of the function.

Junio wasn’t sure if the change was completely correct as he said he no longer trusted his own reading of the http code, but he agreed that it should be merged if gcc wasn’t fixed soon.

Taylor took another look at the patch and found other functions where slot->finished is assigned, so he wondered if a better fix would be to change the int *finished member into a tri-state “UNKNOWN/TRUE/FALSE enum”.

Ævar then sent a version 3 of his patch where he only improved the commit message compared to the previous version. In the new commit message he explains why the other places where slot->finished is assigned are already correct and don’t need any change.

Taylor then agreed with Ævar’s explanations, but Junio wasn’t sure about them, so he changed the commit message a bit, explaining how we could make sure that the change to clear slot->finished is correct by adding the following code before it:
```
        if (slot->finished)
               BUG("the unconditional clearing at the end is wrong");
```
For now the patch has still not been merged into the next branch as Junio hopes that gcc 12.0 will be fixed before it’s actually released. But in case it isn’t, at least we are ready for it.

Developer Spotlight: Victoria Dye

Who are you and what do you do?

Hi! My name is Victoria Dye, and I work as a software developer at GitHub. I spend a lot of my time contributing to Git & some of its downstream forks (Git for Windows and microsoft/git), and occasionally Git Credential Manager (although it’s been a while). I really enjoy solving tough performance problems in software, so I’m hoping to do more of that in Git in the not-so-distant future!
What would you name your most important contribution to Git?

I haven’t been contributing to Git for all that long, so it’s hard to judge the importance of anything I’ve done. That said, I’m pretty proud of the work I’ve done around sparse index and sparse-checkout. It’s been exciting to contribute and see those features mature so rapidly over the past couple months, and I hope it continues to gain traction with users looking for better performance in Git!
What are you doing on the Git project these days, and why?

My focus pretty much since I started working on Git has been on integrating commands with sparse index. Most recently that’s been git stash, which not only requires its own integration, but also the integration of all the commands it shells out to (update-index, read-tree, etc.). The goal of these initial sparse index integrations (including those by Derrick Stolee & Lessley Dennington) is to cover the most popular commands as reported by users at $DAYJOB (git add, git reset, etc.), so the theoretical performance gains of the sparse index can turn into a real improvement to user experience.

Beyond my own work, I’m looking forward to mentoring a GSoC contributor in more sparse index integration! It’s an admittedly complicated topic, but — based on my own experience – working on it can give new contributors an incredible depth of knowledge in Git that’s hard to get elsewhere. Plus, I love mentoring developers and creating a positive environment for them, so I’m excited to have the chance to do that here!
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

It would be great to see the shell script-based test suite rewritten into a unit/integration/end-to-end testing stack. The tests we have are almost exclusively end-to-end (excepting hackery with test-tool or trace2 logs exposing internal functions to test them), so we often have incomplete coverage of some of the trickier code paths (e.g., unpack_trees). And, especially for developers that like test-driven development, it can be a lot easier working with code that has a robust unit testing suite.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

In general, I don’t think there’s a feature that I’d want to completely remove. Git is a fantastic tool in that it lets developers structure their work in whatever way works best for them; something I personally don’t have a great experience with (looking at you, submodules) might just happen to be someone else’s favorite tool.

However, I would absolutely remove an implementation pattern in Git itself: shell script builtins and Git commands shelling out to other Git commands. They’re prone to bugs, difficult to troubleshoot, and can almost always be implemented more efficiently by commonizing the code they’re trying to get out of another command.
What is your favorite Git-related tool/library, outside of Git itself?

I really, really like my current setup of VSCode + GitLens. I used to have a bit of a “text editor is for editing text, Git command line is for source control” attitude and avoided using any integrations between the two, but recently I gave in and installed GitLens. I tend to heavily use the commit history when investigating bugs & learning a new area of the code, so the inline ‘blame’ and commit-message-on-hover in particular make that process about as fast it could be.
What does your mailing list workflow look like?

For submissions, I use GitGitGadget. It really simplifies the process of submitting to Git (especially re-rolls) and, if anything, it prevents me from making silly mistakes with git send-email.

For everything else, I have two email inbox folders: things addressed to me directly (submission feedback, patches I’ve been CC’d on) and “everything else”. For direct feedback/CCs, I try to respond within a couple days if I think I can contribute something valuable to the discussion. The “everything else” folder is set to “automatically mark as read” to avoid a distracting barrage of “unread”s in my inbox, so I typically scan it a couple times a day to stay up-to-date and check whether there’s anything I can help with or review.
Do you think contributing to Git has a high entry barrier? If yes, do you have any suggestions to improve the experience for new contributors?

In my experience, not really (at least, not so high that it excludes would-be contributors). But I think it might seem that way because the mailing list can be super intimidating when you’re looking to get started.

The mailing list is constantly active with complex patches and lots of experienced developers iterating on complicated feedback, so it can be easy to feel as though you can’t contribute much to it or that your code won’t meet the project’s standards. There have been efforts in the past to guide new contributors and help them technically learn the project, but it ultimately comes down to the first interactions someone has with the rest of the mailing that that determines whether or not they stick with it.

In terms of suggestions for improvement, I think it’s important for reviewers to maintain a supportive tone in even highly constructive reviews. A lot can get lost in text communication, so sometimes it’s worth explicitly calling out your appreciation for a contribution. This is especially true for new contributors, but is just as applicable to any reviews.

Another (more concrete) suggestion would be to make it easier for new contributors to find appropriate “starter” features/bugs of different sizes. Other open source projects have issue trackers with a “good first project” tag (and, as a new contributor on other projects, I’ve definitely appreciated them). Although there have been discussions about creating public issue trackers outside the mailing list, to my knowledge nothing like that exists yet for Git, let alone a subset for new contributors.
What is your advice for people who want to start Git development? Where and how should they start?

If you’re not coming in with a clear project or bugfix in mind, it can be really difficult to figure out where to start. If you’re in that position, something that has helped me in the past has been to just start testing things until they break. Read up on a command you find interesting, look for scenarios (e.g. options, sequences) that aren’t well-tested in our existing tests, and start experimenting! Worst case, you can improve test coverage and help us avoid issues in the future; a lot of times, though, you’ll find a bug or an opportunity to add a new option. In any event, the experience will teach you a ton about Git and make you more comfortable with contributing.

And once you have a working change, don’t be afraid to submit it out of fear that it’s not “good enough”. The goal we all share is to make Git as good as it can possibly be, so your contribution – no matter how small or trivial you think it is – is a valuable part of what makes this project succeed.
If there’s one tip you would like to share with other Git developers, what would it be?

Keep learning and trying new things! The Git development community has a vast range of experience across its members – from people who worked on it since the beginning to people making their first open source contribution ever. But it’s also an easy place to get stuck in “your niche” (if you’re lucky, you get stuck with a couple of other people so you can review each others’ work).

Of course, none of us have infinite time to spend on Git. But every once in a while, take a minute to read a contribution from someone you don’t know on a topic you’re not familiar with. Or investigate a bug report on a command you’ve never worked on! Or share your idea for a process we could try (like the Git Review Club)! Not only will you learn something new and improve yourself as a developer, but the collaboration you foster will help all of us improve Git in the long term.

Releases

libgit2 1.4.2
GitLab 14.9.1, 14.9, 14.8.4, 14.8.3, 14.7.6, 14.7.5, 14.6.6
Gerrit Code Review 3.5.1, 3.4.4, 3.3.10,
GitHub Enterprise 3.4.0, 3.3.5, 3.2.10, 3.1.18
GitKraken 8.3.3, 8.3.2, 8.3.1
GitHub Desktop 2.9.12, 2.9.11
Tower for Windows 3.1 (What’s New in Tower 3.1 for Windows blog post)
Tower for Mac 8.1

Other News

Various

Removed unencrypted Git protocol and certain SSH keys in GitHub (removed all support for DSA keys, removed legacy SSH algorithms HMAC-SHA-1 and CBC ciphers, etc.); the motivation behind these changes can be found in the Improving Git protocol security on GitHub article on GitHub Blog.
SSH and Git, meet 1Password: you can now, among other things, enable the SSH agent in 1Password.
Hugging Face uses Gitaly to store Machine Learning related repos.
GitLab is hiring to work on Gitaly.

Light reading

How to Really Use Git: 10 Rules to Make Git More Useful by Bruno Brito on HackerNoon.
Git and GitHub for Marketing Teams by Bruno Brito on Tower’s blog.
The advantages of large, long-running pull requests by David Heinemeier Hanson on hey.com.
How Do I Resolve Merge Conflicts? (without using graphical tools) by Rizèl Scarlett for GitHub, on DEV.to.
How to Rename a Local or Remote Branch in Git by Kolade Chris on freeCodeCamp.
Automatically Format your code on Git Commit using Husky, ESLint, Prettier in 9 minutes by Tapajyoti Bose on DEV.to and Medium.
How Do Git Branches Work? by Anthony Heddings on Cloud Savvy IT.
Teamwork & Git: Dr Max Wilson explains how teams collaborate using Git in a video on the Computerphile channel on YouTube.
- Links to previous videos in this series can be found in Git Rev News Edition #83 and #84.
Speeding Up Commit Graph Walks in Dolt with Materialized Ancestor Closures: Dolt is a version controlled SQL database, first mentioned in Git Rev News #62; you can find more information about versioning and databases in edition #82.

Git tools and sites

Kart stores geospatial and tabular data in Git, providing version control at the row and cell level. It provides repository working copies as GIS databases and files, allowing one to edit them directly in common GIS software without plugins. Support for GeoPackage, PostGIS, Microsoft SQL Server and MySQL formats.
split-patch project consists of the split-patch.py tool, which is git add -p on steroids for patches (*.patch files), allowing to choose in which bucket to put each hunk, and the git-split-commit command (which can be used from interactive rebase) which uses split-patch.py to split the HEAD commit into multiple commits.
DagsHub is a web platform for data version control and collaboration for data scientists and machine learning engineers. The free tier provides 10 GB of DAGsHub Storage, and allows up to 3 collaborators in private projects.
See also the following articles:
- DagsHub: a GitHub Supplement for Data Scientists and ML Engineers by Khuyen Tran in Towards Data Science, a Medium blog.
- DagsHub → Github for Data Science by Shubham Saboo on Towards AI blog.
fds (Fast Data Science), is a CLI for Data Scientists to version control data and code at once, by conveniently wrapping Git and DVC.
- DVC (Data Version Control) was first mentioned in Git Rev News Edition #42.
Jujutsu (jj) is an experimental Git-compatible DVCS. It combines features from Git (data model, speed), Mercurial (anonymous branching, simple CLI free from “the index”, revsets, powerful history-rewriting), and Pijul/Darcs (first-class conflicts), with features not found in either of them.

Credits

Git Rev News Edition 84 (February 28th, 2022)

chriscool — Mon, 28 Feb 2022 11:06:51 +0000

Git Rev News: Edition 84 (February 28th, 2022)

Welcome to the 84th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of January 2022.

Discussions

General

Join us for Review Club!

Josh Steadmon announced that the Review Club meeting he has been organizing at Google for a while is now open to everyone. It happens every other Wednesday at 14:00 Pacific time (UTC-8) via Google Meet.

The first opened meeting happened on Wednesday February 2nd and discussed Elijah’s “In-core git merge-tree” patch series.

Please contact Josh Steadmon at steadmon@google.com if you are interested and want to join.

Reviews

[PATCH] fetch --prune: exit with error if pruning fails

Thomas Gummerer sent a patch so that git fetch, when it’s used with the --prune flag or its -p short form, will not exit with exit status 0 anymore if pruning a ref fails.

Pruning a ref means removing a remote tracking ref, usually a branch, if the ref disappeared on the remote. For example, if a remote called origin has a branch called feature1, then fetching from origin will cause Git to create a remote tracking branch called origin/feature1 on the local machine. After the feature1 branch is removed on origin, subsequent fetches from origin will yield the deletion of the local origin/feature1 branch only if pruning is requested.

Thomas noted in his patch that an error message was already printed on stderr when pruning a ref failed, but it felt like a bug that git fetch was still exiting with the 0 exit status in this case, as this could be interpreted as if no error happened.

Thomas had looked up the commit that introduced pruning, but he couldn’t find if the exit status behavior was “an oversight or intentional”, but it felt like an oversight to him.

Junio Hamano, the Git maintainer, agreed with Thomas about using a non-zero exit status when ref pruning failed, but he was unsure about which actual exit status would be emitted by the code in Thomas’ patch.

Junio also found an issue with the current code as in some cases it appeared that -1 could be passed to exit(). This would result in a 255 exit status, as exit statuses have only 8 bits and are unsigned. He left a #leftoverbits mention related to this in his email, which helps find usually small issues that should be fixed later.

Junio also thought that is probably wasn’t a good idea to error out as soon as an error happens when pruning. It was probably best to continue to fetch and prune as much as possible, “given that we have already paid for the cost of discovering the refs from the other side”.

Thomas’ patch added a new regression test that was then discussed a bit by Junio, who left another #leftoverbits mention related to the fact that many tests in the test script, where Thomas added the new test, were using an old style and might want a cleanup.

Dscho, alias Johannes Schindelin, replied to Junio that it might actually be confusing and unexpected for users if the fetch would continue when pruning failed. He suggested adding a --prune-best-effort option for cases where we might want the fetch to continue as much as possible when pruning fails.

Thomas replied to Dscho that he was unsure what the behavior should be when writing the patch, but that exiting early “felt like the right thing to do for the user”. He said that he would be OK with introducing --prune-best-effort. He wasn’t sure people would actually use it much though, as “it should be very rare that --prune fails”.

Junio replied to Thomas and Dscho that “when we fetch to update multiple refs, we do not stop at the first ref-update failure, but try to do as much as possible and then report an error”, and that --prune should behave similarly.

Thomas also replied separately about Junio’s initial comment related to the actual exit status that would be emitted after Thomas’ patch. He wondered if the exit status should always be 1 when git fetch fails at pruning.

Thomas and Dscho then discussed the new test, following Junio’s comments, and agreed on adding a comment in the code to explain what the test was doing.

Thomas then sent a version 2 of his patch with the changes that had been discussed.

Junio reviewed this new version and decided to merge it down, so this small improvement will be in the next Git version.

Developer Spotlight: Eric Sunshine

(Eric has already been interviewed in Git Rev News #7, September 2015.)

Since your previous interview, have there been changes in who you are and what you do?

About a year after the previous interview, taking on the role of caregiver for a family member consumed the bulk of my time to the point that I was unable to keep up with the Git project or contribute in any meaningful way, and was effectively absent from the project for at least a year and a half. Since returning to the project, my contributions have been far more scarce due to time constraints of “real life” and a new job which I started a few years ago.
You were a long-time RCS, CVS, and Subversion user. Do you miss any features of those version controls systems in Git?

I can say without hesitation that I do not miss any features of those older version control systems. In fact, I can report (perhaps happily) that I have mostly forgotten how to use them. This is true of Subversion, in particular, in which I have had to consult the documentation to tackle even the simplest tasks the couple times I had to use it in the last few years, despite having been a longtime and experienced user.
How are your contributions to Git these days? Code contributions? Code reviews? Others?

In the past, I was generally able to keep up with the mailing list and read most or all patches submitted to the project and often provide detailed reviews, but my Git time is fairly limited these days, so I have to be much more selective about which topics I follow or participate in.

Since I contributed quite a bit to the git worktree command (and am perhaps an “area expert”, especially since Nguyễn Thái Ngọc Duy departed from the project), I pay particular attention to bug reports about that command or topics touching it in some significant fashion. In the case of a bug report, I either provide a fix for the problem myself or help guide some other contributor. In the case of topics which touch git worktree, I try to set aside time to review the topic’s patches carefully and follow along as the topic progresses.

That aside, I also provide reviews for other topics when they fit into my limited Git time, and answer the periodic question on the mailing list, or interact in a discussion if I have something meaningful to offer on the subject.
Are ‘ability to stage changes’ and ‘interactive rebase’ still your favorite Git features? Or do you have new favorites?

Yes they are, and no I do not have new favorites.

In fact, a few years back, I started using the src version control system for managing standalone files (which, although built atop RCS, features a “modern” command line interface quite like Git’s and in no way like RCS’s interface). Although I find src handy for versioning standalone files, I always feel as if my hands are tied when using it since it lacks the very useful features of staging changes and rebasing interactively.

As a consequence, aside from contributing bug fixes and enhancements to the project, I also spent some time significantly improving the fast-import and fast-export round trip fidelity of src. This allows me to temporarily import a src history into Git, which gives me access to Git’s staging and interactive rebasing, and finally convert the history back to src. Yes, it’s a terrible kludge, and a painful one, but at least gives me a way to take advantage of those Git features when absolutely required. I don’t use src often enough presently to justify the development effort, but adding staging and interactive rebasing to the tool directly would be on my wish list for that project.
How does your mailing list workflow look like?

I understand that some developers have special tooling set up to improve the mailing list-centric workflow on the Git project, but I still use a plain email client with no special provisions, and I likely will continue with this set-up as long as it works well enough for my simple needs.

I do find the Git mailing list archive at https://lore.kernel.org/git quite useful and often go spelunking through it when researching some topic or bug report, as well as to fetch sets of patches which I may have already deleted from my local email client. Much more recently, I have also started taking advantage of its NNTP feed (nntp.lore.kernel.org).
Could you elaborate a bit about the email client you use?

I use Gmail in the web browser almost exclusively. Lately, I have been using Thunderbird to access the lore.kernel.org NNTP feed. Infrequently, I use mutt when I need to send a patch inline within a reply when I don’t want the Gmail web interface to modify whitespace or the formatting in general. (I also have Emacs set up for email, thus could use it for the same purpose as mutt, but never actually do so.)

[ Editor’s note: If you’re going to use Gmail in the web browser, ensure “Plain text mode” is checked. Also, see Gmail specific format-patch hints ]
What is your advice for people who want to start Git development? Where and how should they start?

Getting involved in the Git project can be intimidating (I know, even after all these years, I still feel intimidated each time I submit patches), but people on the project are generally quite friendly, and the goal of reviewers is to help you refine your submission so that it can eventually be accepted into the project. After all, that’s why reviewers take the time to read submissions so thoroughly and offer (sometimes in-depth and exhaustive) comments to improve the submission. One thing to note: people who review a lot of patches tend (out of necessity) to be economical with their words, pointing out just the parts of the patch which need improvement and often forgetting to praise the parts which are done well. As such, reviews can sometimes feel cold and off putting, but that is not the intention. Reviewers are genuinely trying to help; they would not put in such effort otherwise.

A good way to learn how the project works is to subscribe to the mailing list and read submissions from active contributors and reviews from regular reviewers. You can learn by example via passive observation. From a patch or patch series, you can learn not only how a patch series should be constructed, but also how an effective commit message is written. By reading reviews, you can learn what reviewers are looking for and how they interact.

To become actively involved in the project, submit a patch, even a small one fixing a bug you found or making a minor improvement to documentation. If you have an idea for a functionality improvement or a new feature, send it to the mailing list. Or, if you just want to contribute without having anything particular in mind, monitor the mailing list for bug reports (as I did when I joined the project) and try to devise a fix and submit it to the mailing list in the form of a patch.

Another way to contribute to the project is by reviewing submissions. Reviews do not need to be extensive or elaborate. A review which points out a minor logic flaw in a patch or highlights a typographical error in a comment or commit message is useful.
If there’s one tip you would like to share with other Git developers, what would it be?

When reviewing a patch, make it clear which of your comments you expect the submitter to act upon and which suggestions can be left to the discretion of the submitter. This is especially important for new contributors who may not be able to distinguish between mandatory changes to the patch and “it might be nice to have” changes. Also let the submitter know that it is okay to push back on a review comment if necessary since newcomers may not realize that doing so is an option.

For a submitter, try to respond to each review comment – even if the response is a simple “OK” or “I agree with all your comments” or “I disagree with this comment because…” – so that reviewers do not feel that their effort has been wasted.

(Oops, that’s two tips, not one. Sorry.)
What would you name your most important contribution to Git?

It is difficult to judge the importance of various contributions. I may instead be able to highlight a few areas in which I have been involved.

Although I do not do many reviews these days, I used to be an active reviewer, and hope that my review comments and suggestions helped improve various submissions in at least some way.

From an end-user perspective, perhaps the my most visible contribution to Git has been all the work I did to improve and enhance the git worktree command and multiple-worktree support in general (though much of the praise for the mechanics of multiple-worktree support belongs to Nguyễn Thái Ngọc Duy who designed and originated the implementation).

From a Git developer perspective, perhaps my most valuable(?) contribution is the so-called chainlint which identifies a specific type of problem in Git test scripts which could, if undetected, allow a test to miss a failure and erroneously report success.
What are you doing on the Git project these days, and why?

As mentioned, my Git time is limited, so my involvement is scaled back. I do try to answer a question here or there or contribute to a discussion if possible, and I review the periodic submission.

Aside from contributing a few bug-fix patches and introducing the git worktree repair command relatively recently, my recent focus has been on a new and much enhanced version of the chainlint tool mentioned above. Although the implementation has been complete for well over a half year (at the time of writing), I am still trying to find time to polish the patch series itself for submission. In the meantime, I did manage to submit a couple other somewhat lengthy patch series in preparation for the new chainlint.

Releases

Git 2.35.1
Git for Windows 2.35.1(2), 2.35.1(1)
libgit2 1.4.1, 1.4.0
GitHub Enterprise 3.3.4, 3.2.9, 3.1.17, 3.0.25, 3.4.0, 3.3.3, 3.2.8, 3.1.16, 3.0.24
GitLab 14.8 14.7.3, 14.7.2, 14.7.1, 14.6.4, and 14.5.4
GitKraken 8.3.0
GitHub Desktop 2.9.9, 2.9.8, 2.9.7
Tower for Mac 8.0 (What’s New in Tower 8 video)

Other News

Various

How some Git fetch performance improvements were made, part 1 and part 2, by the GitLab Scalability team.
Include diagrams in your Markdown files with Mermaid, automatically rendered on GitHub and possibly also in other CommonMark implementations.
More ways to keep your pull request branch up-to-date on GitHub.

Light reading

Cross-fork object sharing in git (is not a bug) by Konstantin Ryabitsev.
Getting Started with Git Bash by Bruno Brito on Git Tower blog.
Inside the Hidden Git Folder - Computerphile by Dr Max Wilson on Computerphile channel on YouTube. Beware a blink and you miss it error about the purpose of the .git/logs/ folder. A link to the previous video on the topic of Git by Dr Max Wilson can be found in Git Rev News Edition #83 (the previous edition).
Protect secrets in Git with the clean/smudge filter by Tomer Figenblat on Red Hat Developer blog.
Git: Switching Unstaged Changes to a New Branch two ways, by Chris Coyier on CSS-Tricks; read also featured comments.

Git tools and sites

Monorepo.tools – Everything you need to know about monorepos, and the tools to build them.
- Announcing monorepo.tools by Juri Strumpflohner for Nrwl.
- You can find the most recent list of pros and cons of monorepos in Git Rev News Edition #81.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Eric Sunshine, Philip Oakley, Bruno Brito and Josh Steadmon.

Git Rev News Edition 83 (January 31st, 2022)

chriscool — Mon, 31 Jan 2022 11:06:51 +0000

Git Rev News: Edition 83 (January 31st, 2022)

Welcome to the 83rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of December 2021.

Discussions

Support

Custom subcommand help handlers

Sean Allred wrote to the mailing list saying that in his company he is distributing a Git subcommand he named git-foo, which can display its own help, but he was struggling to make this work.

Running git foo --help doesn’t pass --help to git-foo, but instead it is rewritten internally in Git to git help foo, which tries to find and then display a help page for git-foo. This could have worked if Sean could install such a page for git-foo along with the help pages for regular Git commands.

On Windows, though, by default help pages are displayed in HTML format instead of the ‘man’ or ‘info’ formats, and these pages are expected to be in a Git for Windows controlled installation directory that he’d rather not touch.

One solution he suggested would be to not rewrite git foo --help to git help foo if the foo command is not a builtin.

Ævar Arnfjörð Bjarmason replied to this suggestion that this might not please everyone, as git send-email --help and git annex --help were currently expected to show the manual, even though these commands are not builtins.

Dscho, alias Johannes Schindelin, also replied to Sean saying that just looking whether the command is a builtin or not might not be enough, as Git also installs scripts or executables, and provided some example code implementing an is_in_git_exec_path() function.

Ævar and Dscho then discussed a bit if such a function was needed as Ævar pointed that we already have a way to dump builtins, other known commands and commands unknown to Git, using respectively:
- git --list-cmds=builtins
- git --list-cmds=main
- git --list-cmds=others
Meanwhile Erik Cervin Edin replied to Ævar’s initial reply to Sean saying that when a Git alias is configured for foo and it’s used with --help, the user is told that foo is an alias for another command, and the help page for the other command is displayed. So he suggested doing something similar for non-builtin commands that are missing help pages.

Erik also mentioned that using git-foo --help directly or git foo -h, instead of git foo --help, would allow git-foo to handle everything.

brian m. carlson replied to Erik that for man pages it might not be possible to distinguish a missing page from another error. He then wondered if there is a similar environment variable as MANPATH for HTML pages, as MANPATH on Unix systems instructs man to search for pages in the directories specified in this variable. He also suggested installing the HTML documentation alongside Git’s, as it’s expected on Unix systems to have all man pages installed into the same place.

Junio Hamano, the Git maintainer, then agreed to this suggestion.

Erik replied to brian and Junio that there was no standard or convention around HTML documentation, and talked about the help.htmlPath configuration variable that could be used to tell Git where to look for HTML pages. He also suggested falling back to searching a missing HTML page starting at the path of the command.

The discussion continued for some time between Erik, Junio, Philip Oakley and Dscho, especially around the topic of aliases.

Then Junio spotted the GIT_HTML_PATH environment variable in the code, and noticed that it can currently be used to specify just one directory for HTML pages, while MANPATH can be a colon-separated list of directories. So he suggested changing the code to allow GIT_HTML_PATH to also be a colon-separated list of directories. This would allow people to install HTML pages in directories without the need of administrator rights.

It looks like no one has yet started working on this though.

Releases

Git 2.35.0, 2.35.0-rc2, 2.35.0-rc1, 2.35.0-rc0
Git for Windows 2.35.0(1), 2.35.0-rc2(1), 2.35.0-rc1(1), 2.35.0-rc0(1)
GitLab 14.7 14.6.3, 14.6.2, 14.5.3, and 14.4.5, 14.6.1
GitHub Enterprise 3.3.2, 3.2.7, 3.1.15, 3.0.23

Other News

Various

Highlights from Git 2.35 by Taylor Blau on GitHub Blog.
Linux Foundation launches Open Source Software Development, Linux, and Git certification, and three new training courses on the edX platform (including Git for Distributed Software Development (LFD109x)).
Introducing new Git features to Visual Studio 2022 by Taysser Gherfal on Microsoft Visual Studio DevBlog.

Light reading

Signing Git Commits with SSH Keys by Danilo Bargen (available since Git version 2.34).
Git Overview - Computerphile, a video by dr Max Wilson, filmed and edited by Sean Riley.
Awesome Git Aliases and More Awesome Git Aliases by Landon Schropp on Dawid Walsh Blog.
Git Organized: A Better Git Flow by Annie Sexton on Render.com Blog; though a better solution would be to use interactive rebase, as described in comments for this article on DEV.to.
No code reviews by default (to move faster) by Thomas Paul Mann of Raycast (and how it works for them).
How to Make a Component That Supports Multiple Frameworks in a Monorepo by Rob Levin on CSS-Tricks.
How Git Works Under the Hood by Faisal Albasu on freeCodeCamp.
Advanced Git Concepts You Should Know by Tapajyoti Bose on The Practical Dev (also known as DEV.to).
How to Write Better Git Commit Messages – A Step-By-Step Guide by Natalie Pina on freeCodeCamp; this article talks also about the Conventional Commits specification, first mentioned in Git Rev News Edition #52.
How to check commit message and branch name with git hooks without any new installation, a short article by Anibal on DEV.to.
How Bad Can It Git? Characterizing Secret Leakage in Public GitHub Repositories by Michael Meli, Matthew R. McNiece, Bradley Reaves in NDSS 2019; via the morning paper article by Adrian Colyer.
The Pull Request Paradox: Merge Faster by Promoting Your PR Adding more context to our Pull Requests got them merged two days faster. Here’s how it works. By Dan Lines.
What’s in a Good Error Message? Some thoughts on ensuring error messages are useful to the reader. By Gunnar Morling.
Let’s Talk about Error Messages More thoughts on error messages, by Brien King.

Git tools and sites

git-perl-critic - Command-line interface for the Perl Git::Critic module, reporting Perl::Critic failures (that is, code violating Perl best practices) only on lines changed in the current Git branch. By Curtis “Ovid” Poe.
Dura is a background process that watches your Git repositories and commits your uncommitted changes without impacting HEAD, the current branch, or the Git index (staged files). With this tool you should not ever lose your work if you’re using Git. Written in Rust by Tim Kellogg.
ResumableGitClone (2017) is a Bash shell script to clone a large repo without retrying again and again, by using a deepening shallow clone.
git-pull-run is an npm package which automatically runs commands like npm install when fetching changes from Git, but only if certain files have changed. Extended version of the script presented in Automatically Install NPM Dependencies on Git Pull.
Husky.Net is a Git hooks manager for .NET, among others making it possible to run linters against staged Git files. Inspired by husky, lint-staged, a few other tools, and by Using C# code in your git hooks article by Max Hamulyák (2019).
- lint-staged was first mentioned in Git Rev News #45
- husky was first mentioned in Git Rev News #63

Credits

Git Rev News Edition 82 (December 30th, 2021)

chriscool — Thu, 30 Dec 2021 11:06:51 +0000

Git Rev News: Edition 82 (December 30th, 2021)

Welcome to the 82nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of November 2021.

Discussions

General

Peff is taking a break from Git

Peff, alias Jeff King, announced on the mailing list that he is going to take a five months break from Git starting at the end of December. He is also stepping down from Git’s PLC (Project Leadership Committee), the entity that represents Git within Software Freedom Conservancy.

Peff has been involved in the project for 15 years and has contributed a huge number of patches as well as an enormous amount of reviews, support and discussions.

He also used to maintain git-scm.com, the main site of the project. It looks like Taylor Blau, who has been working at GitHub with Peff, will take over maintaining this site.

Along with others on the mailing list, let’s thank Peff for his contributions to Git and Git Development Community!

Support

misleading message printed when worktree add fails

Baruch Burstein posted a bug report on the mailing list saying that he ran git worktree add <path> <branch>, where <branch> was an already checked-out branch, and saw a message that seemed to indicate that the command was a success, when in fact it was not.

Eric Sunshine replied to him asking if he saw something similar as:
```
% git worktree add ../foo bar
Preparing worktree (checking out 'bar')
fatal: 'bar' is already checked out at '.../wherever'
```
Baruch replied that he actually saw the messages emitted by Git in a different order:
```
fatal: 'master' is already checked out at 'C:/Users/bmbur/temp'
Preparing worktree (checking out 'master')
```
Eric then diagnosed the following:

Okay, that’s happening because the ‘Preparing’ message is sent to stdout, whereas the ‘fatal’ error is sent to stderr, and the streams are being flushed on Windows in a different order than what we typically see on Unix platforms even though the ‘Preparing’ message is actually output first by the code.

He then proposed to have the die() function, which is emitting the ‘fatal’ error, or the vreportf(), which is used by die() to emit the ‘fatal’ error, flush stdout before emitting an error. This would fix not only the issue Baruch saw, but also other similar issues in other parts of the code.

Randall S. Becker replied to Eric that his proposed fix was “probably a good idea” as “there is no guarantee even in Unix regarding stream buffer flushing”.

Eric posted an RFC patch implementing his proposed fix. The patch added a call to fflush(stdout) in vreportf() just before this function calls fflush(stderr) and before it actually writes a message on stderr.

Junio Hamano, the Git maintainer, replied to the patch wondering if flushing stdout when it is going to a pipe talking to another process could cause issues. He noticed that the HTTP backend code uses vreportf() in this way, though he said that any code using stdio “cannot precisely control when the buffered contents are flushed anyway”, so the patch might be OK.

Jeff King, alias Peff, then started a discussion about the possibility of arbitrary flushing causing some code to block, which might create a deadlock, as some other code might be waiting for something from the now blocking code. Eric suggested that this could be addressed by flushing stdout only if stdout is attached to a terminal, though he thought this would be “rather ugly”.

Ævar Arnfjörð Bjarmason chimed in to ask about the warning() and error() functions that also call vreportf(), but Peff replied that they were probably OK.

Meanwhile Peff also replied to Eric’s patch wondering if “status messages like this go to stderr anyway”. He remarked that

in general our approach in Git is more “if it is the main output of the program, it goes to stdout; if it is chatter or progress for the user, it goes to stderr”.

He also explained that it works consistently on glibc as “stdout to a terminal is line buffered by default, so the ‘Preparing’ line is flushed immediately”. But even on Linux, without a terminal, like when both stdout and stderr are redirected to the same file, for example with git worktree add ../foo bar >out 2>&1, the output to stderr appears before the one to stdout.

Eric replied to Peff saying he had considered emitting the ‘Preparing’ line on stderr instead of stdout, as Peff suggests, but he thought that it’s not documented and not very consistent that this kind of output from Git should go to stderr, and also that it could be a regression if people relied on that. He suggested adding a fflush(stdout) to git-worktree’s code and “live with that localized ugliness”.

Peff agreed that Git has not been very consistent, but he said that more careful reviews and “laying out guidelines could help”. He also pointed to a previous discussion from 10 years ago where he had “laid out his mental model” about this topic.

He also noticed that the ‘Preparing’ line was marked for translation, so “not reliably machine-readable anyway”. He also pointed to a previous commit that moved some git clone output from stdout to stderr for similar reasons.

Eric then agreed with Peff about sending a different patch to move the ‘Preparing’ line output to stderr and another patch to improve documentation about this topic. Eric also noticed that this output had been changed significantly 3 years ago without any complaints.

He then sent a patch to improve our documentation about this. A second version of this patch was eventually merged to the master branch after Eric took into account some reviews by Fabian Stelzer, Junio, Peff and Philip Oakley to improve some wordings.

Ævar and Junio discussed a bit further the “you shouldn’t write anything that isn’t an error” view of the world, and Ævar cited the “chronic” utility.

Eric also sent a small patch series that moved the ‘Preparing’ line output to stderr and fixed a minor problem in the git worktree documentation he noticed along the way.

This patch series started a small inconclusive discussion between Ævar, Eric, Peff and Junio about automating the synopsis and maybe other parts of the documentation from the code or other ways to avoid duplication and mismatches.

The patch series was eventually merged as is to the master branch though.

Developer Spotlight: Randall S. Becker

Who are you and what do you do?

I am Randall S. Becker, president of Nexbridge Inc. I have been a software developer and architect for many decades. Aside from the obvious SCM domain knowledge, my interests are around data structures, performance, computability, and languages. About 10 years ago, I joined the ITUGLIB Technical Committee, which is an Open-Source group that maintains code for the HPE Nonstop community - the platform was originally called Tandem Computers Inc.
What would you name your most important contribution to Git?

I have been maintaining the code associated with the HPE NonStop platform for the past six years and was key to its successful port to both the x86 and ia64 variants of the platform. In addition, I keep an eye out for changes that may put the port at risk and run the CI/CD environment that builds and tests Git on the platform.
What are you doing on the Git project these days, and why?

I am currently working on the .git/config includeIf function for worktrees, planning a threaded version of the port, which is challenging considering the nature of the platform and community. We have to maintain compatibility with some old versions of the operating systems that lack some more modern capabilities. The platform is an MPP architecture without kernel level threads (yet), and the port to POSIX threads is very messy with the operating system wrappers we have to use.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

There are really three areas where I would want to work. The first, most important, is improving multi-level signing capabilities in Git to support the software supply chain. I could leave it at that, but the full set of requirements in various countries are not yet fully fleshed out. Another two, purely to support the NonStop community is converting the code written in Go (Git LFS) into C and making it part of the standard product. The other is migrating the interpretive code to a C99-standard code base.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I would move directly to SHA-384 or SHA-512 and toss both SHA-1 and SHA-256 as soon as possible. The same applies to any signing capabilities to support 8K or higher key sizes in defense against future hacking using the capabilities quantum computers.
What is your favorite Git-related tool/library, outside of Git itself?

This is a bit of self-promotion for my company, and I apologise for that. We build façade-style interface facilities that allow legacy platforms, including HPE NonStop and IBM’s TSO/ISPF environments to have full Git experiences despite the native file systems not supporting POSIX-like hierarchies. These are Git clients that map file system attributes and structures to and from what Git can understand. Our NonStop product was recently added to the HPE price book. These products allow older codebases to share in the benefits of real DevOps capabilities without having to rely on proprietary knowledge and processes. I am the chief architect of those products.
Do you happen to have any memorable experience with respect to contributing to the Git project? If yes, could you share it with us?

I think the most satisfying experience was the few months it took to contribute all the code associated with the NonStop port. It was a huge pain to maintain the separate fork even with Git’s awesome merge capabilities. Being allowed to be lazy is a dream of many developers and cutting down the time and effort spent on each release to a simple push of the Jenkins “Build Now” button frees up a lot of time.
What is your advice for people who want to start Git development? Where and how should they start?

Learn about Merkle Trees and general data structures.

I am still learning when it comes to general functional contributions. Watching how others contribute is really crucial if you have any hope of your contribution being accepted.
If there’s one tip you would like to share with other Git developers, what would it be?

For every change you make, think about the security implications. Think about what a hacker might do to compromise Git or an organisation using Git before you move forward, no matter how good an idea might seem. The last thing you want is to have your contribution show up as a Critical Vulnerability Exposure on the NIST database.

Releases

Git 2.34.1
Git for Windows 2.34.1(1)
GitHub Enterprise 3.3.1, 3.2.6, 3.1.14, 3.0.22, 3.3.0, 3.2.5, 3.1.13, 3.0.21, 3.2.4, 3.1.12, 3.0.20
GitLab 14.6 14.5.2, 14.4.4, and 14.3.6, 14.5.1, 14.4.3, 14.3.5, 14.2.7
Bitbucket Server 7.19
Gerrit Code Review 3.5.0
GitKraken 8.2.1, 8.2.0
GitHub Desktop 2.9.6, 2.9.5

Other News

Various

Google Summer of Code (GSoC) 2022 is expanding to everyone 18 years or older, to different project sizes and to flexible timelines.

Light reading

Stochastic bisection in Git by Jonathan Corbet on LWN.net. The patches in question were proposed for inclusion in Git by Jan Kara.
Fedora revisits the Git-forge debate by Jake Edge on LWN.net.
A brief history of code search at GitHub by Pavel Avgustinov on GitHub Blog.
Working with a Monorepo, co-authored by Claus Matzinger, Stephanie Visser and Martin Tirion; on Microsoft’s CSE Developer Blog. You can find most recent list of pros and cons of monorepos in Git Rev News Edition #81.
How to Create a React Typescript Monorepo with Git Submodules by Alex Eagleson on DEV.to.
Git Pull, for the Holidays, a song from The Daily WTF; Lyrics - Remy Porter and James Rushin, Music - James Rushin.
How to Reset a Single Git File and Why by Bobby Jack on MakeUseOf.
Merging multiple git repos with their commit history by Thomas Klausner (domm). Note that there might be a better, simpler solution for the problem.
Using the Reflog to Restore Lost Commits by Tobias Günther on CSS-Tricks is the next part of the Tower Git Client’s “Advanced Git” series.
Git Commands Cheatsheet: Advanced (20+ Git Commands Advanced) by aashiya123 on DEV.to.
10 useful Git tips to improve your workflow by Jordan Soo Yen Yih on DEV.to.
Top 30 Git Commands You Should Know To Master Git CLI by Tara Prasad Routray on Level Up Coding by gitconnected.com (a Medium.com blog).
Git scraping: track changes over time [to a web site or a web service] by scraping to a Git repository and git-history: a tool for analyzing scraped data collected using Git and SQLite by Simon Willison on his weblog.
Top 5 Best Git Extensions For VS Code (You must have) by Nomadev on DEV.to. You can find a similar list in Git Rev News Edition #77.
So you want Database Version Control?, So you want a Git Database?, and So you want Git SQL? by Tim Sehn on DoltHub Blog. Dolt and DoltHub were mentioned in Git Rev News Edition #62. Those blog posts talk about different ways databases and version control can connect:
- version controlling database schema, aka database migrations:
  - Liquibase, mentioned in Git Rev News #60
  - Redgate Deploy
  - Planetscale
  - Alembic for SQLAlchemy (not mentioned in those articles), mentioned in Git Rev News #60
  - Sqitch (not mentioned in those articles), mentioned in Git Rev News #60
  - Entity Framework Migrations (not mentioned in those articles)
  - Flyway by Redgate (not mentioned in those articles), mentioned in Git Rev News #60
  - DBmaestro (not mentioned in those articles)
  - skeema for MySQL, MariaDB, and Percona Server (not mentioned in those articles), mentioned in Git Rev News #60
  - gh-ost: GitHub’s online schema migration for MySQL (not mentioned in those articles), mentioned in Git Rev News #60
- version controlling queries:
  - VersionSQL
  - DBT (Data Build Tool)
  - Git Your SQL Together (with a Query Library) by Caitlin Hudon (2018) (not mentioned in those articles), mentioned in Git Rev News #46
- data versioning (version control within schema, or Slowly Changing Dimension):
  - Noms
  - TerminusDB for graph or document databases; whitepaper about TerminusDB was mentioned in Git Rev News #60
  - Dolt for relational databases, mentioned in Git Rev News Edition #62
  - LiteTree: SQLite with Branches which is a modification of the SQLite engine to support branching (not mentioned in those articles), mentioned in Git Rev News #43
- Git as database (with own query language):
  - GitRows for JSON and CSV files
  - Git as a NoSQL database by Kenneth Truyers (2016), mentioned in Git Rev News #28
  - Turning Git into an application database by Peter Ruttkay-Nedecký (2019)
- SQL for querying Git repos:
  - Gitbase by source{d} aka src-d - using MySQL, mentioned in Git Rev News #48; note that the link on the source{d} site no longer works
  - MergeStat - using SQLite
  - Gitana (repo, docs, paper)- using MySQL (not mentioned in those articles, possibly because it started as a research project), mentioned in Git Rev News #7 and #48
- storing a database in Git:
  - SQLite where databases are files
  - gitSQL exporting flat file SQL statements of objects from the database for storage in a Git repository

Git tools and sites

BBChop is a tool in Python by Ealdwulf Wuffinga implementing a bisection algorithm which works on intermittent bugs (experimental code). BBChop is based on Bayesian Search Theory.
Soft Serve is a self-hostable Git server for the command line, written in Go. It is configurable with Git, you can create repos on demand with git push, and you can browse repos with an SSH-accessible TUI.
GitLive is a proprietary extension with a free tier for Visual Studio Code, JetBrains IDEs, and Android Studio, providing real-time collaborative support, giving insight about what other developers in the team are working on. It supports GitHub, Bitbucket, GitLab (including self-hosted) and Azure DevOps repository hosting services.
GitLive was mentioned as VS Code extension in Git Rev News Edition #77.

Credits

Git Rev News Edition 81 (November 29th, 2021)

chriscool — Mon, 29 Nov 2021 11:06:51 +0000

Git Rev News: Edition 81 (November 29th, 2021)

Welcome to the 81st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of October 2021.

Discussions

Reviews

[PATCH 0/3] Fun with cpp word regex

Johannes Sixt sent a small patch series about improving C++ (also called ‘cpp’) support in the userdiff mechanism. This mechanism is used by Git to generate diffs that are customized to specific programming languages (like C, shell, Perl, MATLAB, etc.) or markup languages (like HTML, Markdown, TeX, etc.).

Especially one of the patches splits the regex that was matching all the numbers into 3 different regexes:
- one for floating point numbers that begin with a decimal point,
- one for decimal and octal integers as well as other floating point numbers, and
- one for hexadecimal and binary integers.
The result is that expressions like 1+2, 1.5-e+2+f and .l are not considered numbers any more and are properly parsed for diff purposes in C++ files.

Another patch in the series allows single-quote characters as digit separators according to the C++17 standard, like in 3.141'592'654 or 0xdead'beaf.

The third and last patch prevents the <=> generalized comparison operator (also called ‘spaceship’ operator) introduced in C++20 from being split into <= and >.

Ævar Arnfjörð Bjarmason replied to Johannes suggesting to add a few tests in the t/t4034/cpp/ directory, where test files for the cpp userdiff mechanism reside.

Johannes agreed with Ævar and sent a second version of his patch series. This series included 2 new patches that improved existing tests and added new tests for problematic behavior that the other patches were fixing.

Ævar commented on this series saying that it was much improved, but it could perhaps be even better if:
- the C++ support was split up from the C support,
- some tests were added first, before the behavior was changed, and
- some tests could be added for code comments, as he wondered if tokens that often occur in natural language, like " and &, were still correctly handled when they appeared in code comments.
Johannes agreed with the second point, but wasn’t interested in working on the others.

Ævar and Johannes discussed a bit further if it was worth doing something for code comments, but Johannes concluded that it wasn’t.

Johannes then sent a third version of his patch series. In this new version test cases for single-quote characters as digit separators and the <=> generalized comparison operator were moved to a new commit before the commits supporting these features.

Later on, Johannes noticed that the single-quote character as digit separator is problematic and requires a more sophisticated implementation. For example, as implemented the character literal '.' would be split into '. and '. The support for digit separators was eventually reverted.

This patch series was then merged into the master branch, so that Git 2.34 that was recently released has better support for C++ in diffs.

Releases

Git 2.34.0, 2.34.0-rc2, 2.34.0-rc1, 2.34.0-rc0
Git for Windows 2.34.0(1), 2.34.0-rc2(1), 2.34.0-rc1(1), 2.34.0-rc0(1)
Bitbucket Server 7.18
GitHub Enterprise 3.3.0, 3.2.3, 3.1.11, 3.0.19, 3.2.2, 3.1.10, 3.0.18
GitLab 14.5 14.1.8, 14.4.2, 14.0.12, 13.12.15, 14.4.1, 14.3.4, and 14.2.6
Gerrit Code Review 3.4.2, 3.3.8, 3.2.14, 2.16.28
GitKraken 8.1.1

Other News

Various

Derrick Stolee and Lessley Dennington talk about the future of Git at scale.
Highlights from Git 2.34 by Taylor Blau on GitHub Blog, and
Git 2.34 sets new merge default, speeds things up for monorepo users by Julia Schmidt on Dev Class.
Require pull requests without requiring reviews on GitHub.
Deprecating Atlassian account password for Bitbucket API and Git activity (for Git over HTTPS) on Bitbucket.

Light reading

Get lazy with lazygit by Tahsin on DEV.to. Lazygit was first mentioned in Git Rev News Edition #42 (August 22nd, 2018).
Should You Use HTTPS or SSH For Git? by Anthony Heddings on Cloud Savvy IT.
How To Switch a GitHub Repository to SSH Authentication by Anthony Heddings on Cloud Savvy IT.
5 Underrated [free] resources to learn Git and GitHub by ifrah on DEV.to.
- GitHub Minesweeper by Profy was mentioned in Git Rev News Edition #80 (October 30th, 2021).
- Oh My Git! game by bleeptrack and blinry was mentioned in Git Rev News Edition #72 (February 27th, 2021).
The “Advanced Git” series by Tobias Günther on CSS-Tricks, courtesy of the Tower Git client, (mentioned in Git Rev News #80), continues:
How to become a Git expert! by Sagar Barapatre on DEV.to.
What is .gitkeep? How to Track and Push Empty Folders in Git. by Kealan Parr on freeCodeCamp.
How to Write Good Commit Messages with Commitlint by Anish De on freeCodeCamp.
Removing a .env file from Git history (or any other accidentally added, committed, and pushed file) by Chris Bongers on Daily Dev Tips.
The case against monorepos by Lee Atchison on Info World.
- You can find various arguments for and against monorepos in Git Rev News editions #4, #9, #47 (pros and cons), #72, #78, not counting articles about improving the performance of large repositories, which monorepos usually are.
How to do pull request reviews by Mage company on DEV.to.
Git Rebase for Preventing Merge Commits by jen chan on DEV.to.
Signed git pushes by Konstantin Ryabitsev (2020).
DeployBot Configuration with Git LFS by Markus Cadonau (2020).

Git tools and sites

commitlint is a tool written in JavaScript and running on Node.js (that is, an npm tool) that helps your team with adhering to a commit convention.
Conventional Changelog is an npm tool to generate changelogs and release notes from a project’s commit messages and metadata.
Git Command Explorer is a web application to help you find the right commands you need without digging through the web, made by Summitech company.
Arlo’s Commit Notation is a notation for small commit messages that shows the risk involved in each step and the author’s intention, conveyed in the first 3 characters of the commit summary line.

Credits

Git Rev News Edition 80 (October 30th, 2021)

chriscool — Sat, 30 Oct 2021 11:06:51 +0000

Git Rev News: Edition 80 (October 30th, 2021)

Welcome to the 80th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of September 2021.

Discussions

Reviews

[PATCH] MyFirstContribution: Document --range-diff option when writing v2

Glen Choo sent a patch to the mailing list to improve the Documentation/MyFirstContribution.txt tutorial, so that it suggests using the --range-diff option of git format-patch when sending a new v2 version of an already sent patch series.

The Documentation/MyFirstContribution.txt tutorial was initially created by Emily Shaffer in 2019, and has been a popular way for developers to start learning how to improve Git.

Eric Sunshine agreed with Glen’s idea, but made a few comments on some minor issues, like using --range-diff=psuh over --range-diff psuh..psuh-v2 and adding a link to the git range-diff documentation.

Junio Hamano, the Git maintainer, also replied to Glen, saying that the tutorial should promote a slightly different workflow to work on an updated branch.

He suggested creating a topic branch or a lightweight tag, for example called psuh-v1, that points to the old tip of the psuh branch, and continuing to work on the psuh branch to prepare the version 2 of a patch series, instead of creating and working on a psuh-v2 branch.

He also commented that the commands given in the tutorial might not work well when the branch corresponding to the first and second patch series had the same commits after diverging from the master branch.

Glen agreed with Junio’s suggestion, though they discussed it a bit further.

Bagas Sanjaya replied to Glen’s initial email saying he wasn’t sure if the --range-diff option was necessary, but Eric disagreed with him saying:

“Anyone who does any serious amount of review on this project finds it tremendously helpful to have both a prose description of the changes (“Changes since v1…” plus a link to the previous submission) and a mechanical range-diff or interdiff.”

Glen then sent a version 2 of his patch that took into account Junio’s and Eric’s suggestions. Especially it recommends marking the tip of the psuh branch corresponding to version 1 and continuing to work on the psuh branch to prepare the version 2.

Eric Sunshine replied to this new patch with a number of suggestions to improve some wordings and explanations. Glen agreed with Eric’s suggestions.

Bagas then suggested creating a psuh-v2 branch and continuing to work on it, but this was against what Junio had suggested earlier, so Glen didn’t agree with that. He agreed with a wording improvement that Bagas suggested though.

Philip Oakley chimed in to discuss some wording when the version number would change again later to 3, 4, etc. But after further discussion with Glen and Bagas, he agreed with the original wording.

Glen then sent a version 3 of his patch taking into account Eric’s and Bagas’s suggestions. This version of the patch was later merged into the master branch, so we can now enjoy a better tutorial explaining an improved workflow.

Developer Spotlight: David Aguilar

Who are you and what do you do?

My name is David Aguilar and I work as a Staff Software Engineer - Architecture Lead for a small team of devops and infrastructure engineers at the Walt Disney Animation Studios. Outside of work I’m a husband and a caretaker, so my time is usually pretty occupied these days.

Cats, art, music and mountain biking are a few of my favorite things outside of the usual technical topics.
What would you name your most important contribution to Git?

We started adopting Git as our VCS of choice relatively early in Git’s history around 2007 at Disney Animation. One of the things that I tried to do early on was to listen to some of the loudest and most vocal critics and get to the root of their complaints about Git at the time.

One of the tools that fell out of this was git difftool. The criticism at the time was along the lines of, “I can’t believe Git is missing such a fundamentally basic workflow that even tkcvs / tkdifff have”. Git already had git mergetool for helping resolve merge conflicts at the time, so adding support for diff workflows seemed like a natural extension of Git’s capabilities.

The original difftool RFC patches started as a crude shell script that drove the diff itself and handled interacting with external diff tools directly. Feedback from the Git mailing list improved it by making it use git diff’s GIT_EXTERNAL_DIFF functionality when it first landed in git.git’s contrib/ area. difftool eventually graduated out of contrib/ to become a builtin tool, and its implementation was heavily refactored so that it can share all of its tool-specific implementation details with git mergetool.

Mergetool and difftool are a small yet key part of day-to-day Git usage for many developers and is a great example of a general internal need that was best addressed by proposing a solution to the Git development community so that it can be evolved and improved alongside Git.
What are you doing on the Git project these days, and why?

Beyond difftool, I’m the author and maintainer of Git Cola, a powerful yet simple GUI for Git [source code].

Git Cola started as a learning project. I wanted to better learn PyQt and Git in 2007, and creating a user interface for Git’s unique and powerful staging area features seemed like a perfect project. One of the features I use very often is its keyboard-driven interactive staging feature. If you’ve ever wanted to stage, unstage, and revert edits at a line-by-line granularity, using a unified interface (no need to jump between git add -p and git checkout -p) that is keyboard-driven with vim-inspired hotkeys for power users that understand Git and its strengths, then Git Cola might be just the tool for you.

Git Cola has been gradually improved over the last 14 years and is extremely stable and capable these days. It includes everything from a drag+drop rebase editor (itself reusable as a GIT_SEQUENCE_EDITOR that is provided as a standalone git-cola-sequence-editor tool) and encourages users to leverage Git’s unique strengths by making it easy for new Git users to follow Git “best practices” such as creating fixup commits and rebasing their work.

These days I do try to keep an eye on difftool (a big thank you to Johannes Schindelin for rewriting difftool in C in the context of the Git for Windows improvements) and continue to improve Git Cola.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I would really like to see more effort put into getting the ideas/improvements from the Microsoft Scalar project integrated into Core Git. Props should go to Microsoft for working alongside the Git project towards up-streaming this work. Focusing on the scaling challenges that come up when working with huge repositories is an area I am hopeful will continue to improve. Git continues to be perceived as being “bad at binary files”, and “not industrial-grade like Perforce” by the GameDev community, and that’s something that can definitely be improved.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Submodules are useful and serve a specific use case, but working with them involves a lot of little paper cuts that makes them painful for users that aren’t ready to deal with their complexities. Double-commits (having to commit in the sub and super-project) is one of the little paper cuts that really shouldn’t exist were the capability to compose and operate on multiple repos intrinsic to Git itself. This is by no means a simple problem.

On the bright side, git submodule has been getting a lot of attention recently. I don’t think I would remove them without a compelling replacement in their place.

Sometimes the downsides of submodules are more so about how they are used than how they are implemented. Whenever I encounter a project that does git submodule update or git clone in their make build process, I get a bit nervous. That’s not really Git’s fault, though.

Transitioning to SHA-256 is an obvious area that would be much simpler if it didn’t have to deal with backwards compatibility.
What is your favorite Git-related tool/library, outside of Git itself?

Git Cola =)

Git Annex is a really great tool for archival purposes and is what I use for backing up my personal files. It’d be nice if it didn’t have to exist, but I’m very happy that it does. Git Annex has some concepts that are unique and different from Git LFS and other solutions in this space.

I somewhat recently wrote a Git workflow tool for myself that I call garden. Garden is basically a glorified way to operate over ad-hoc collections of Git trees. I wrote it because I have lots of Git Annexes and other repos in arbitrary places that I often need to iterate over and perform custom commands or other operations on. garden lets me do that. I’m not sure if anyone would ever find it useful, but I wrote it for myself so that’s okay.

I often find myself cloning random repos, figuring out how to build them (lots of projects have bespoke build systems), and then later figuring out how to run and interact with the repo. I used to have a smattering of shell scripts to build and run various projects. I now use garden for holding all of these disparate bits in a single place so that the workflows become easier to transport (and store in Git). URLs, multiple worktrees, the remotes associated with each worktree (useful for recreating a worktree with dozens of remotes from contributors) and custom commands for operating in the context of the worktrees can all be grouped together into a single “garden file” that can be shared and reproduced on another machine.
Do you happen to have any memorable experience w.r.t contributing to the Git project? If yes, could you share it with us?

I personally learned a lot from the Git development community. The review process is one that focuses on quality and perfection (Git doesn’t settle for “good enough”) with a strong eye towards maintainability and not breaking existing users. The Git project teaches us to create commits that are reviewable, to make independent, logically-separate changes, and to describe our changes well. These principles, alongside the idea that all code should be reviewed and collaborated on, is something that has helped transform our internal development processes.
What is your advice for people who want to start Git development? Where and how should they start?

If you’ve never built Git yourself from scratch then the quickest way to get started is to clone the repo and run make. Start looking around the code base, read the git log messages, and start reading the new contributor documentation in the Documentation/ folder.

A lot of effort has been put into making it easier to contribute to Git itself, but the community won’t know about any of the pain points unless you reach out and illuminate what might be blind spots in our practices.

Set up your mail filters and subscribe to the Git mailing list once you’re ready to start diving deeper. There is a lot of activity, but there’s also no shortage of things you can learn by reaching out and engaging with the community.

Releases

Git 2.33.1
Git for Windows 2.33.1(1)
libgit2 1.3.0
Gerrit Code Review 3.3.7, 3.2.13
Bitbucket Server 7.17
GitHub Enterprise 3.2.1, 3.1.9, 3.0.17
GitLab 14.4, 14.3.3, 14.3.2, 14.3.1, 14.2.5, and 14.1.7, 14.0.11, 14.1.6
GitKraken 8.1.0, 8.0.1
GitHub Desktop 2.9.4
Git Cola 3.11.0

Other News

Various

Notes from the Git Contributors’ Summit 2021, virtual, Oct 19/20, a thread by Johannes Schindelin.
- One of the topics was having public “Git chalk talks”, an idea which has now its own thread.
Software at Scale 35 - Maintaining Git [for Windows] with Johannes Schindelin, a podcast.

Light reading

A 16 Year History Of The Git Init Command by Jacob Stopak on Initial Commit.
Clean Conventional Commits by Jonathan Irvin on DEV.to.
- The Conventional Commit message standard was first mentioned in Git Rev News Edition #52.
How to Remove Git Version Tracking from a Folder and How to Delete Git Branches On Local and Remote Repositories by Anthony Heddings on Cloud Savvy IT.
Git: Moving from Master to Main (as the name of the default branch), challenges faced by Jumping Rivers company; note however that they got the origin history of Git using ‘master’ wrong in this article.
Branching Strategies in Git by Tobias Günther on CSS Tricks is a part two post in the “Advanced Git” series.
- See also Patterns for Managing Source Code Branches in #73 and Ship / Show / Ask: A modern branching strategy in #79.
Code Review from the Command Line by Jake Zimmerman (2018).
The Thing About Git by Ryan Tomayko (2008).

Git tools and sites

git-autofixup automatically creates fixup commits for topic branches.
git-foresta is a text-based git log graph viewer, written in Perl, using Unicode for drawing. It is a modified version of git-forest (written in Perl by Jan Engelhardt), see below.
hxtools by Jan Engelhardt is a collection of small tools and scripts, which include git-author-stat (commit author statistics of a git repository), git-blame-stat (per-line author statistics), git-revert-stats (reverting statistics), and git-forest (display the commit graph).
Lab is a tool that wraps Git, making it simple to clone, fork, and interact with repositories on GitLab, including seamless workflows for creating merge requests, issues and snippets. It was inspired by and is similar to the hub tool that does the same for GitHub.
- GLab for GitLab, and gh for GitHub are more interactive command line tools, that do not aim to be familiar to a git and to leverage it.
The Advanced Git Kit is a 10 part video course for free from makers of the Tower Git client.
GoGit is a project under OpenCode’21 that aims to improve the Git and GitHub skills of the contributors by completing some tasks. The tasks are being specified in the Issues section of the project’s GitHub repo.
GitHub Minesweeper by Profy is a GitHub bot to learn a professional Git and GitHub workflow.

Credits

Git Rev News Edition 79 (September 30th, 2021)

chriscool — Thu, 30 Sep 2021 11:06:51 +0000

Git Rev News: Edition 79 (September 30th, 2021)

Welcome to the 79th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of August 2021.

Discussions

General

GSoC (Google Summer of Code) 2021 End

Congratulations to the two students who had been accepted to work on Git as part of the GSoC 2021 as they successfully passed all the evaluations!
- Atharva Raykar worked on the Finish converting submodule to builtin project. He was co-mentored by Shourya Shukla and Christian Couder. He posted 2 final blog posts about it, some Reflections on Working With the Git Community and a Technical Report.
- ZheNing Hu worked on the Use ref-filter formats in git cat-file project. He was co-mentored by Hariom Verma and Christian Couder and posted a final blog post about it.

Support

bug in git fsck?

Last July, Ulrich Windl asked the mailing list whether git fsck should be able to cleanup orphaned branches. He pointed to a question he asked on StackOverflow as he wanted to get rid of obsolete branches after filtering a repo.

git fsck was complaining about a branch called bitmap-generic saying notice: HEAD points to an unborn branch (bitmap-generic), because that branch was pointing to a commit that didn’t exist anymore after filtering the repo, and he couldn’t delete that branch as git branch -d errored out with fatal: Couldn't look up commit object for HEAD.

Junio Hamano replied to Ulrich that “HEAD pointing at an unborn branch is not even a corruption”, as that’s what happen to the default branch when a repo is initialized.

Ulrich replied that he might have been confused by git fsck and suggested updating the documentation to explain what “unborn” means. Ævar Arnfjörð Bjarmason then agreed with Ulrich that “fsck’s error messages/reporting is pretty bad”. He said that he had been working on it though.

Meanwhile René Scharfe replied to Junio saying that git branch -D (-D is a shortcut for --delete --force) should delete a branch pointing to an unexisting commit, instead of requiring users to first reset the branch to some known commit using git branch --force and then to delete it with git branch --delete. In this reply René even provided a patch called “branch: allow deleting dangling branches with --force” that implemented what he suggested.

Ulrich and René then discussed how to actually force a branch in a way that it can then be deleted. The issue was that Ulrich tried to force the dangling branch, using git branch --force bitmap-generic when the current branch wasn’t a valid one, so the dangling branch wasn’t restored to a valid commit.

To René’s patch, Junio replied that he felt the filtering process Ulrich used shouldn’t have left dangling branches hanging around in the first place. He agreed though that it should be easy to recover from “such a deliberate repository corruption”.

René’s patch then fell through the cracks for several weeks, until the end of August when René resent it.

Junio replied that the test in René’s patch went “against the spirit” of a recently merged patch series by Han-Wen Nienhuys that was preparing tests for the new reftable ref backend.

The reftable backend was initially proposed and developed in 2017 by Shawn Pearce. An implementation of it has then been integrated in JGit, and Han-Wen has been working for some time on versions of this backend for Git and libgit2.

Junio suggested to change parts of the test that were creating or testing refs to use higher functions to manipulate refs, instead of directly manipulating loose ref files like .git/refs/heads/dangling.

Junio, Ævar, Han-Wen, Ulrich and René then discussed different ways to change the test, like using the REFFILES test prerequisite. They wondered if such a dangling ref could also happen with the reftable backend, and it seemed that this could indeed happen.

Han-Wen suggested the ref-store test-helper’s update-ref command to manipulate refs instead. Ulrich proposed implementing a new --disarm-safety-belt option to disable checks for testing purposes. Ævar suggested a workaround using an alternate object directory.

Meanwhile Ævar commented a bit on René’s resent patch. And René replied to the comments, especially noting that git tag -d would delete a dangling tag even without --force.

René then sent a version 2 of his resent patch with an updated test that was now independent from any ref backend.

Junio, Ævar and René discussed the patch a bit more, after which René sent a version 3 with a few more improvements to the test.

As this version of the patch has since been merged into the master branch, Git will soon allow to delete dangling branches more easily.

Developer Spotlight: Josh Steadmon

Who are you and what do you do?

I’m a Software Engineer at Google, and I work on a team dedicated to Git. Outside of work, I’m a husband and a new dad, which doesn’t leave me much time for anything else :).

Git is actually my first experience as a professional developer. Up until I joined the Git team in 2018, my career had been in system administration and reliability engineering.
What would you name your most important contribution to Git?

Probably the addition of fuzz tests. Not so much due to impact so far (although it has found a few small bugs), but because of the opportunity for future work in this area. If I had more time, I’d love to look into having a proper fuzz tester for client/server communication, for example.
What are you doing on the Git project these days, and why?

Until recently, the majority of my work has been internal performance monitoring of Git usage by Google developers. Lately I’ve been winding down my work on monitoring and starting to look into improving performance and the user experience with submodules. Only the very beginnings of that have started to show up on-list so far.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I think I’d echo my former coworker Brandon Williams (edition 28), and work on cleaning up the global state. For a new-ish developer who doesn’t have full history on all the various subsystems, it can be difficult to follow the logic when there’s lots of non-local state being modified.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Not so much to remove as change: I wish it was easier to move away from SHA-1 hashes. I’m very happy that brian m. carlson has been working on supporting SHA-256.
What is your favorite Git-related tool/library, outside of Git itself?

I’m a huge fan of git-annex and use it to keep my ever-growing pile of PDFs and ebooks synced and organized across various devices. I also use it to archive primary sources in a homebrew personal knowledge base.

Releases

libgit2 1.2.0
GitLab 13.12.12, 14.3, 14.2.4, 13.12.11, 14.0.10, 14.2.3, 14.2.2, 14.1.4, and 14.0.9
Bitbucket Server 7.16
GitHub Enterprise 3.1.8, 3.0.16, 2.22.22, 3.2.0, 3.1.7, 3.0.15, 2.22.21
GitKraken 8.0.0
GitHub Desktop 2.9.3

Other News

Various

3 Reasons to Upgrade Git For The First Time Ever by swyx on DEV.to.
Emacs discusses web-based development workflows by Jake Edge on LWN.net.

Light reading

Optimizing Git’s Merge Machinery, Part VI by Elijah Newren on Palantir Blog, the final in the series.
Ship / Show / Ask: A modern branching strategy by Rouan Wilsenach on martinFowler.com, showing different ways of doing Continuous Integration with a Pull Request workflow, and explaining when to use which method.
GitHub merges ‘useless garbage’ says Linus Torvalds (as new NTFS support added to Linux kernel 5.15) by Tim Anderson in The Register.
How to Protect Your Private Email Addresses in Git & GitHub? on GeeksforGeeks (GitHub specific with respect to hiding your email while still counting your contributions).
Advanced Git Workflow Tips by Khalid Abuhakmeh on JetBrains’ The .NET Tools Blog, additionally explaining how to perform the actions from Rider’s .NET IDE UI.
Increasing developer happiness with GitHub code scanning by Sam Partington on the GitHub Blog; the examples use the Go language. GitHub code scanning uses the CodeQL semantic code analysis engine.
GitHub Workflow, Merge and Rebase, actually more about Git than about GitHub, by AaronDski on DEV.to.
How to Use Git Hooks For Commit Automation by Anthony Heddings on CloudSavvy IT.
Run RuboCop on git commit with Overcommit Gem by Prabin Poudel on his blog. Overcommit gem was mentioned in Git Rev News #63, along various other hook management tools.
Git Flow Is A Bad Idea video by Dave Farley of Continuous Delivery. An interesting perspective on the Git branching model. Worth reflecting on the underlying assumptions and management approaches that make Git branches such a bad idea, in that particular context.
Full Git Tutorial. Basics for the new user. Leap to Part 7 for the Git Log Fully Explained.

Git tools and sites

Glean: System for collecting, deriving and querying facts about source code.
5 JetBrains plugins to upgrade the built-in Git support to the next level! by Thomas Scott on DEV.to. A similar list for Visual Studio Code was presented in Git Rev News Edition #77.
GitHub Web Editor: FREE VSCode in the browser by Davide ‘CoderDave’ Benvegnù on DEV.to, about the lightweight code editor, based on Visual Studio Code (VSCode), that is a part of GitHub Codespaces. The GitHub Codespaces project was mentioned in Git Rev News Edition #63.

Credits

Git Rev News Edition 78 (August 31st, 2021)

chriscool — Tue, 31 Aug 2021 11:06:51 +0000

Git Rev News: Edition 78 (August 31st, 2021)

Welcome to the 78th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of July 2021.

Discussions

Support

Bug report: GIT_CONFIG and user.email/name

German Lashevich sent a bug report about an issue when using the GIT_CONFIG environment variable.

He gave an example where he sets the user.name and user.email config variables to some values in a temporary /tmp/git-test/.gitconfig config file, and then sets GIT_CONFIG to point to this file.

When he then tried to commit some changes, Git errored out with an “Author identity unknown” error and instructions about how to set the current account’s default identity. He expected that the values of the user.name and user.email variables set in the temporary config file would have been taken into account.

Peff, alias Jeff King, replied that GIT_CONFIG is a historical wart that isn’t used by all of Git, but only the git config command, and even there git config --file should be used instead.

He suggested using GIT_CONFIG_GLOBAL or GIT_CONFIG_SYSTEM which are available since v2.32.0. They instruct Git to read a specific file instead of the usual global (usually /etc/gitconfig) or system-level ($HOME/.gitconfig and $XDG_CONFIG_HOME/git/config) config files respectively.

German thanked Peff saying GIT_CONFIG_GLOBAL was what he needed.

Junio Hamano, the Git maintainer, replied to Peff that reading the GIT_CONFIG documentation gave a misleading impression as it didn’t say that GIT_CONFIG was only for the git config command.

Peff agreed with Junio saying that the documentation hadn’t been updated since 2007, when GIT_CONFIG really did impact other commands, and that he was sending a small patch series to improve the situation.

Taylor Blau and Martin Ågren reviewed the patches and discussed them a bit with Peff and Junio.

The patch series was later merged into the master branch, and the documentation improvements are now available in the recently released Git 2.33.

Releases

Git 2.33.0, 2.33.0-rc2, 2.33.0-rc1, 2.33.0-rc0
Git for Windows 2.33.0(2), 2.33.0(1), 2.33.0-rc2(1), 2.33.0-rc1(1), 2.33.0-rc0(1)
GitHub Enterprise 3.1.6, 3.0.14, 2.22.20, 3.1.5, 3.0.13, 2.22.19
GitLab 14.0.8, 14.2.1, 14.2, 14.1.3, 13.12.10, 14.1.2, 14.1.1
Gerrit Code Review 3.3.6, 3.2.12, 3.1.16, 3.4.1
GitKraken 7.7.2, 7.7.1
GitHub Desktop 2.9.2, 2.9.1

Other News

Various

Highlights from Git 2.33 by Taylor Blau on GitHub Blog.
Treeverse raises $23M to bring Git-like version control to data lakes: lakeFS.
GitHub has shut down its Git password authentication on August 13, 2021; you should preferably use token-based authentication instead; support for SSH keys continues.

Light reading

Optimizing Git’s Merge Machinery, Part V by Elijah Newren on Palantir Blog.
How to write release notes by Drew DeVault.
From a Single Repo, to Multi-Repos, to Monorepo, to Multi-Monorepo by Leonardo Losoviz on CSS-Tricks.
- The idea of monorepos was first mentioned by this name in Git Rev News Edition #4, with Edition #47 including many links to discussions about their advantages and disadvantages.
Visualizing a codebase: how can we automatically “fingerprint” a codebase to see its structure at a glance, by Amelia Wattenberger on GitHub Next.
The History Behind Git by Ahmed Gouda (also on DEV.to).
Getting geeky with Git, an 11 part series by Marcin Wanago.
New in Git: switch and restore by Dragos Barosan (new to the author; git switch and git restore appeared in Git 2.23 in 2019).
A Guide to Git Stash by Pragati Verma on DEV.to.
How to Fix, Edit, or Undo Git Commits (Changing Git History) by Anthony Heddings on CloudSavvy IT.
5 Ways to Undo Mistakes with Git by Tobias Günther on SitePoint.
5 Git Tricks Every Developer Should Know by Shadid Haque on DEV.to.
Git for Managing Small Projects by Rob “drtorq” Reilly on The New Stack, the first part in a planned series of tutorials on Git.
Git: Fetch and Merge, don’t Pull, an old blog post by Mark Longair about his tips related to fetching and merging versus pulling, that was discussed a long time ago on the mailing list.
Best practices for writing code comments by Ellen Spertus about writing better code comments.

Git tools and sites

lakeFS is an open source tool that transforms your object storage into a Git-like repository. It enables you to manage your data lake (storing unprocessed data) the way you manage your code. Supports AWS S3, Azure Blob Storage and Google Cloud Storage; works seamlessly with all modern data frameworks such as Spark, Hive, AWS Athena, Presto, etc.
- Existing products comparable to LakeFS include tools such as DVC (first mentioned in Git Rev News Edition #42), Pachyderm (first mentioned in Git Rev News Edition #49), and Meltano (first mentioned in Git Rev News Edition #42).
CITATION.cff files, which use Citation File Format (CFF), are plain text files with human- and machine-readable citation information for software (and datasets). Code developers can include them in their repositories to let others know how to correctly cite their software. Supported by GitHub, Zenodo and Zotero.
GitUI is a blazing fast terminal based GUI for Git written in Rust, meant to work reliably even on large repositories. Similar to tig.

Credits

Git Rev News Edition 77 (July 31st, 2021)

chriscool — Sat, 31 Jul 2021 11:06:51 +0000

Git Rev News: Edition 77 (July 31st, 2021)

Welcome to the 77th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of June 2021.

Discussions

Reviews

[PATCH] builtins + test helpers: use return instead of exit() in cmd_*

Ævar Arnfjörð Bjarmason sent a patch to the mailing list that changed some cmd_*() functions so that they use a return statement instead of exit(). He further said that it is legitimate for the SunCC compiler on Solaris to complain about the exit() calls, as they would skip any cleanup made after them.

The cmd_*() functions are important in the architecture of Git, as there is one such function for each Git “builtin” command, and the function is called by run_builtin() in git.c to perform the command. For example when git log is launched, the cmd_log() function is called by run_builtin().

Felipe Contreras reviewed the patch and found it obviously correct.

Peff, alias Jeff King, also said that it looked like simple and obvious conversions, but he wondered what was SunCC complaining about, especially if it didn’t know about NORETURN, and would complain about many other exit() calls.

NORETURN is a special statement to tell the compiler that a function doesn’t return, but instead uses a function like exit() to stop the current process.

Phillip Wood also wondered if SunCC would complain about die() calls, which use exit() underneath.

Ævar then sent a version 2 of his patch, with no code change but explaining that SunCC actually complains when there’s no NORETURN while we declare a cmd_*() function to return an int. He replied to Peff with the same explanation and added that around half of SunCC warnings are legitimate, and that he had already been sending miscellaneous fixes for 15-20 of them.

Junio Hamano, the Git maintainer, replied to the version 2 patch. He especially had an issue with the part in the commit message that said that directly exit()-ing would skip the cleanups git.c would otherwise do, like closing file descriptors and issuing errors if it failed. He considered that it was “not a crime” for the functions to exit themselves as file descriptors are closed when we exit and “if we do have clean-ups that are truly important, we would have arranged them to happen in the atexit() handler”.

Junio anyway thought that the patch was still “a good idea because it encourages good code hygiene”.

Ævar replied to Junio that file descriptors are indeed closed when we exit, but the errors we could get when closing them would not be reported. He pointed to previous commits that had been merged back in 2007 to make sure IO errors were properly reported after the cmd_*() functions return, and said that “the atexit() handlers cannot modify the exit code (both per the C standard, and POSIX)”. He also discussed a bit how glibc allows atexit() handlers to munge the exit code though it’s not portable behavior.

Junio replied that Ævar was right and that “we leave a final clean-up for normal returns (i.e. when cmd_foo() intends to return or exit with 0) to be done by the caller”.

The patch was later merged into the master branch and the next version of Git will better signal IO errors, thanks to SunCC and people running it to compile Git on Solaris machines.

Releases

Git for Windows 2.32.0(2)
libgit2 1.1.1
Gerrit Code Review 3.3.5, 3.2.11
GitHub Enterprise 3.1.3, 3.0.11, 2.22.17
GitLab 14.1.0, 14.0.6, 14.0.5, 14.0.4, 13.12.8, and 13.11.7, 14.0.3, 13.12.7, 14.0.2, 13.12.6, and 13.11.6
Bitbucket Server 7.15
GitKraken 7.7.0

Other News

Various

Tower 7 - The New Commit Experience
NO_COLOR is a proposed universal standard of disabling colored text output in command-line software programs. The website also documents which software has adopted this standard and when support was added, and for projects that did not adopt this standard it tries to document how to otherwise disable color.

Light reading

How to Get Better with Git by Ana Vela provides a list of free and paid resources to help you boost your Git know-how.
Git quick tips #1: git commit –fixup and Git quick tips #2: Working with many branches by Michael Kohl.
Git For Data Engineers by Kovid Rathee: a shortish guide to source control for data engineers, data analysts, and data scientists.
How to Learn Git Slowly by Samuel Faure.
How NOT to use Git in Practice. Ten Git usages, you should know to avoid. by Tapas Adhikary on GreenRoots Blog.
Elevate your Git-fu! by Abhay Krishna Arunachalam on DEV.to.
How to Collaborate on Components across Projects with Bit by Eden Ella on DEV.to. The Bit project was mentioned in Git Rev News Edition #45.
On the Evilness of Feature Branching - A Tale of Two Teams, one novice practising trunk-based development, the other very experienced using GitFlow, by Thierry de Pauw.
- See also Patterns for Managing Source Code Branches by Martin Fowler, mentioned in Git Rev News Edition #63.
Things I wish Git had: Commit groups by Daniel Janus - to have advantages of topic branch workflow when using “rebase and merge” workflow.
Git Squash Simplified by Pawel Borkar on DEV.to.
How Git Branches Work: Git Branches Tutorial, by Beau Carnes, on freeCodeCamp.
git update: the odyssey for a sensible git pull by Felipe Contreras.
Optimizing Git’s Merge Machinery, Part IV by Elijah Newren on Palantir Blog.

Git tools and sites

diffsitter creates semantically meaningful diffs that ignore formatting differences like spacing. It does so by computing a diff on the AST (abstract syntax tree) of a file rather than computing the diff on the text contents of the file. diffsitter uses the parsers from the tree-sitter project to parse source code. Written in Rust, it is very much a work in progress.
The best 6 VS Code extensions to supercharge Git by Jamie Swift on DEV.to.
GitLive is a Visual Studio Code extension to see which branch your teammates are on in VS Code.
Git Immersion provides a guided tour that walks through the fundamentals of Git, inspired by the premise that to know a thing is to do it. Another variant of Git Immersion was mentioned in Git Rev News Edition #38.

Credits

Git Rev News Edition 76 (June 27th, 2021)

chriscool — Sun, 27 Jun 2021 11:06:51 +0000

Git Rev News: Edition 76 (June 27th, 2021)

Welcome to the 76th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of May 2021.

Discussions

Support

[BUG] Unix Builds Requires Pthread Support

Not long after 2.32.0-rc0 was released, Randall S. Becker reported to the mailing list that a patch series from Jeff Hostetler, which introduced a “Simple IPC Mechanism”, broke the build for the NonStop x86 and ia64 platforms. This build defines NO_PTHREADS, as supporting pthreads on these platforms is considered to cause “a bunch of other issues”.

It seems that Jeff patch series has introduced a file, called ipc-unix-socket.c, which contains a call to the pthread_sigmask() function part of the pthreads library, which is of course not linked to when NO_PTHREADS is defined.

Randall suggested a “simple, but probably wrong fix” which just surrounds the call to pthread_sigmask() with #ifndef NO_PTHREADS and #endif.

Peff, alias Jeff King, replied to Randall that usually an “async” mechanism is used for tasks that can be performed by several workers in parallel, and that underneath this mechanism can be implemented both using different processes and using different threads. At build time, depending on the availability of pthread, one or the other implementation is selected.

Peff couldn’t tell though, if the “async” interface that the IPC mechanism defines can actually be implemented using processes. Anyway he proposed an improved patch to fix the build by just removing the files implementing the mechanism from the build if NO_PTHREADS if defined, similar to dealing with NO_UNIX_SOCKETS.

Jeff Hostetler, who had implemented the IPC mechanism, then replied to Peff that the mechanism was heavily threaded and that there was no point in trying to “fake it” with processes. So he agreed with Peff’s patch, which conditionally removes it from the build.

Peff replied to Jeff asking if he wanted to pick his patch up from there and produce a polished patch before the 2.32.0 release. Jeff then agreed to do that, and sent a more elaborate patch based on Peff’s patch and on some discussions about it that happened in the meantime between Peff and Randall.

Junio reviewed Jeff’s patch and made some suggestions, which after further discussion were integrated in version 2 of the patch.

A version 3 soon followed to fix the build for people using CMake instead of make. This version was merged before 2.32.0-rc1.

Developer Spotlight: Han-Wen Nienhuys

Who are you and what do you do?

I’m Han-Wen Nienhuys. I work at Google, where I manage the Gerrit team. If you don’t know yet, Gerrit is the Git-based code review system that Google uses for large open source projects, such as Android and Chrome.

For a while, Shawn Pearce was my boss. I got to know him because of previous Git adventures at Google: I created git5, a wrapper around our internal Perforce (‘p4’) deployment as a side project. You can still see some traces of this, if you look at the commit history of git-p4.
What would you name your most important contribution to Git?

I didn’t contribute many patches to Git directly, but here is my biggest one so far:

Gerrit accepts code for review through a git push command, and user studies showed that Gerrit’s error messages didn’t stand out among the verbose terminal output. I added colorization for keywords like “ERROR” and “WARNING” to draw more attention.
What are you doing on the Git project these days, and why?

Gerrit uses Git as a database, storing all review metadata (comments, LGTMs) in Git itself, which is extremely cool, but it also creates extremely ..interesting.. scaling problems for Git and JGit.

One area of scaling is the ref database: Gerrit stores both metadata and each version of a code review in a separate ref. As a result, large projects, such as Chrome, now have several millions of refs in their repository. Handling those efficiently is a challenge. Shawn designed reftable to solve these problems, and partly implemented it in JGit, but he never got round to updating the Git project itself to use the format.

At the end 2019, I thought it would be an interesting and fun project to drive that project further. I did severely underestimate how complicated it would be to do brain surgery on Git itself, though, so 1.5 years later, it still hasn’t merged. Working on Git itself (as opposed to Gerrit, and managing the team) is a side project, so progress hasn’t been as fast as I’d like it to be.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Rewrite Git on top of libgit2. Or even better, rewrite it in Go. Hacking on Git is a fun trip down memory lane, because the last time I wrote C seriously, I was half my current age. It doesn’t feel very productive though, in part because of limitations of the language (memory management, lack of strings/maps/GC etc.).

I realize that’s ambitious, and would turn off a lot of the current contributors, however, I think much could also be gained by structuring the program better (e.g. banish global variables, introduce more unit tested abstraction boundaries), and that could be achieved by rewriting parts on top of libgit2.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The packed/loose ref backend. All of Git storage is user-accessible (under the .git directory), but the packed/loose ref storage is extra insidious, because you read/write it using cat and echo, which invites people to break abstraction boundaries.
What is your favorite Git-related tool/library, outside of Git itself?

It’s Gerrit, of course.

Releases

Git 2.32.0, 2.32.0-rc3, 2.32.0-rc2
Git for Windows 2.32.0(1), 2.32.0-rc3(1), 2.32.0-rc2(1)
Bitbucket Server 7.14
GitHub Enterprise 3.1.2, 3.0.10, 2.22.16, 3.1.1, 3.0.9, 2.22.15, 2.21.23, 3.1.0
GitLab 14.0.1, 14.0, 13.12.5, 13.12.4, 13.12.3, 13.12.2, 13.11.5, and 13.10.5
GitHub Desktop 2.9.0, 2.8.3

Other News

Various

The 2021 Gerrit Community Survey results have been published, showing a robust increase of the overall number of users and the adoption of the most recent versions of Gerrit Code Review.
Got typos? Git 2.32 lands, finally offers way to reword commits [easily].

Light reading

Crypto Mining is Killing All Free CI/CD Platforms by Davide ‘CoderDave’ Benvegnù is a blog post on Dev.to and a video on YouTube. The platforms affected include GitLab, TravisCI, CircleCI and GitHub Actions; the CI providers have limited their free tiers, or have to spend much effort on combating crypto miners abusing the platform in response.
Pulling GitHub into the kernel process by Jake Edge on LWN.net (free link for not subscribed) describes attempts to make it possible to submit patches to the Linux kernel via GitHub pull requests (PR). While at it, it also mentions various attempts and tools to improve an email-based workflow.
- For submitting patch series to the Git project via GitHub pull requests, there is GitGitGadget, described in Git Rev News Edition #42.
A Random Walk Through Git by Bakken & Bæck is a weird in-depth tour through Git and some of its internals, including reflog, interactive rebase, bisect and rerere.
How to never type passwords when using Git by Michelle Mannering on Dev.to.
Confusing Terms in the Git Terminology by Pragati Verma on Dev.to.
Git Good - The magic of keeping a clean Git history post by Chris Manson is designed to help you form a solid mental model while working with Git both professionally and in an open source project, and how to ensure you are following best practices to make the process easier for everyone.
Merge vs rebase by Evandro Myller on Dev.to.
Git Log: How to Use It by James Gallagher (2020), one of Git tutorials on Career Karma blog.
Fixing basic mistakes with Git by Abhinav Pandey on Dev.to.
After CRUD: Intro to Git and basic workflows by John Mosesman (2019).

Git tools and sites

A Git history visualization page by Jeff Palmer <jeffrey.palmer@acm.org> shows “An Interactive Development History” of Git in three columns: project and contributor statistics, relative cumulative contributions by contributor, and aggregated commits by contributor by month with milestone annotations. Jeff wrote an associated blog post about how he created the visualization, and he’s also looking for feedback and ideas for milestones or features he could add.
git undo: We can do better describes the git-undo tool that is a part of the git-branchless suite of tools; it can undo bad merges and rebases with ease, and even some rarer operations. This git undo tool was made possible by a recent addition to Git: the reference-transaction hook (not yet present on the GitHooks.com site, mentioned in Git Rev News Edition #43; the reference-transaction hook was described in #75).
- The GitUp client also supports undo/redo via snapshots, also by adding additional plumbing on top of Git. This tool was first mentioned in Git Rev News #5.
- The undo Git alias described in Git Undo post by Enrico Campidoglio simply uses the reflog, and is less capable. This post was mentioned in Git Rev News #19.
git-branchless is a suite of tools, written in Rust, to help you visualize, navigate, manipulate, and repair your commit history. It’s based off of the branchless Mercurial workflows at large companies such as Google and Facebook.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Han-Wen Nienhuys, Luca Milanesio and Jeffrey Palmer.

Git Rev News Edition 75 (May 27th, 2021)

chriscool — Thu, 27 May 2021 11:06:51 +0000

Git Rev News: Edition 75 (May 27th, 2021)

Welcome to the 75th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of April 2021.

Discussions

General

Git participates in GSoC (Google Summer of Code) 2021

The following two students have been officially accepted to work on Git as part of the GSoC 2021:
- ZheNing Hu will work on the Use ref-filter formats in git cat-file project. He will be co-mentored by Hariom Verma and Christian Couder. His first blog post about it is up.
- Atharva Raykar will work on the Finish converting submodule to builtin project. He will be co-mentored by Shourya Shukla and Christian Couder. His first blog posts about it are also up.
Thanks to the students who applied and worked on micro-projects, but couldn’t be selected! We hope to continue to see you in the community!
The top 1% of commit trailers

Felipe Contreras posted a fun analysis of how often various commit trailers (reviewed-by, tested-by, etc) appear in the git.git project.

Setting aside signed-off-by (which all contributions must include), the most common trailers are acked-by (1945 occurrences) and reviewed-by (1729 occurrences), together accounting for almost half of all trailers.

The next 4 most common trailers give a great insight into just how much collaboration goes on in the git.git project: helped-by (1336), reported-by (960), mentored-by (379), and suggested-by (281).

Perhaps most interesting is the long list of trailers that have only been seen once, though now that this list is out there we may see more of deemed-obviously-correct-by, worriedly-acked-by, and cheered-on-by in the future.

One can also note that this distribution roughly follows Zip’s law; the 10th most popular line (“improved-by”) is about 1/10 as popular as the 1st.

This script can be used to replicate the analysis.

Reviews

[PATCH] [GSOC] pretty: provide human date format

ZheNing Hu sent a patch to the mailing list to add the new %ah and %ch formatting options to the “pretty formats”. The “pretty formats” are the main way for users to customize the output of the git log, git show, git rev-list, and git diff-tree commands.

These formats are specified by the --pretty[=<format>] or --format=<format> command line flags, where <format>is the actual “pretty format”, and can be either a “built-in format”, like oneline, raw, short, medium, etc, or format:<string>, which is called a “format string”.

These format strings work in a similar way to printf() formats, as they can contain placeholders starting with a % character, that will be expanded by the command. For example %H will be expanded to print the commit hash, %an the author name, etc.

A lot of placeholders already exist. For the author date, there are: %ad, %aD, %ar, %at, %ai, %aI and %as. For the committer date, there are the corresponding %cd, %cD, %cr, %ct, %ci, %cI and %cs ones. Each pair of these placeholders uses a different date format. For example, %aI and %cI use the “strict ISO 8601 format”.

Formats %ad and %cd, though, are special as they use the format specified by the --date=<format> command line flag, so for example with --date=iso-strict, %ad and %cd will behave in the same way as %aI and %cI.

ZheNing’s patch added the new %ah and %ch placeholders that would behave in the same way as %ad and %cd with --date=human. The rationale for the patch being that there are placeholders corresponding to most of the --date=<format> options except --date=human.

Taylor Blau was the first to review ZheNing’s patch and found it “pretty good”, as it was similar to a previous patch by René Scharfe that added the %as and %cs placeholders for dates in the “short date format”. ZheNing acknowledged that he indeed learned from René’s patch.

Philip Oakley, though, commented on the documentation part of the patch suggesting to add an example similar to YYYY-MM-DD for the short format. ZheNing replied that in the “human format” a date could take many forms, so he said he would rather add links to the documentation of the “human format”.

ZheNing then sent a version 2 of his patch where he had added the links. Philip suggested further small superficial changes to the link and the related text added in this version though.

Meanwhile Ævar Arnfjörð Bjarmason sent a small patch series that made a “couple of trivial changes” to the tests related to %aI and %cI, and at the same time suggested ZheNing to make similar changes to the tests in his patch.

ZheNing then sent a version 3 of his patch, taking Philip’s and Ævar’s suggestions into account. This patch contained a typo, though, so ZheNing sent a version 4 of his patch.

As the version 3 of the patch had already been merged to the “next” branch before ZheNing sent the version 4, the typo got noticed by Martin Ågren who sent a small patch series fixing this typo as well as another unrelated one.

Eventually both ZheNing’s patch and Martin’s patches were merged into the “master” branch, so that their improvements will appear in the soon upcoming Git version v2.32.0.

Developer Spotlight: Patrick Steinhardt

Who are you and what do you do?

I’m a software developer working at GitLab, more specifically in the team working on Gitaly. Gitaly is our RPC interface to all Git repositories, so it is the backbone to all things Git at GitLab.

In my own free time, I love to tinker with my Gentoo-based systems and tailor them to my own needs, which results in occasional drive-by patches to all kinds of open source projects to scratch my own itches.
What would you name your most important contribution to Git?

To me, this is the introduction of the reference-transaction hook, which gets executed whenever a reference is about to be updated. This allows tight control over all reference updates happening in a given repository in a command-agnostic way. At GitLab, we use this hook to coordinate reference updates across multiple replicas of the same repository such that we can be sure that all nodes have the same state and move to the same state.

My most important contributions I’d not locate in the Git project itself though, but instead in libgit2. While I unfortunately haven’t found the time to contribute to it lately, I’ve done a lot more work on libgit2 than I did on Git. And there it’s probably the initial introduction of support for worktrees, maintenance of the CMake build system and work on the gitconfig subsystem.
What are you doing on the Git project these days, and why?

My current work is mostly focussed on tuning performance of some areas we have found to be slow for gitlab.com. This has motivated the recent introduction of a new git-rev-list(1) filter which allows to filter by object type via --filter=object:type=<type>. This makes it easy to find for example all blobs introduced between two revisions.

And right now I’m trying to devise a new implementation of the object connectivity check performed by git-receive-pack(1) whenever a push gets accepted on the server side. Depending on the repository’s shape, the current implementation can be a major bottleneck and take dozens of seconds to compute even for small pushes. You may have noticed this check when it says “Checking connectivity” on a push.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’m obviously biased coming from the libgit2 project, but I’d really love to further push the libification of Git. There has been great progress on this front already to make internal C interfaces look more like the typical interfaces you’d see from a linkable library. But my dream would be to merge the efforts of Git and libgit2 such that Git also provides an official library which can be linked against in your own program.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Tough question. There’s many user-facing commands which could benefit from a more consistent design, but my take is that these probably could provide an improved user interface while still retaining backwards compatibility.

But what I’d really love to get rid of is the file-based reference backend. It works reasonably well to represent references as file paths in smallish repositories, but even there it imposes limitations which are only a result of its implementation. It’s also inefficient for bigger repositories and does not really allow for atomic modification of multiple references at once. There luckily is ongoing work on the reftable backend, which fixes many of the shortcomings, but it will likely still take some time to land.
What is your favorite Git-related tool/library, outside of Git itself?

I guess the answer to that question is going to be obvious by now: libgit2.

Releases

Git 2.32.0-rc1, 2.32.0-rc0
Git for Windows 2.32.0-rc1(1), 2.32.0-rc0(1)
GitLab 13.12, 13.11.4, 13.11.3, 13.11.2, 13.10.4, and 13.9.7
Bitbucket Server 7.13
Gerrit Code Review 3.4.0, 3.3.4, 3.2.10, 3.1.15, 3.2.9, 3.1.14
GitHub Enterprise 3.0.7, 2.22.13, 2.21.21, 3.1.0, 3.0.6, 2.22.12, 2.21.20
Magit 3.0.0
Forge 0.2.0
GitKraken 7.6.1, 7.6.0
GitHub Desktop 2.8.1, 2.8.0

Other News

Various

Linus Torvalds was interviewed on the Tag1 Consulting site about 30 Years Of Linux and about Git. A part 2 of the interview not related to Git has also been published.
GitHub announced that security keys are now supported for SSH Git operations via ecdsa-sk and ed25519-sk key types.

Light reading

Scaling monorepo maintenance by Taylor Blau on GitHub Blog, with reverse indexes, multi-pack bitmaps, and geometric repacking.
Developing a script in small steps by Volker Kroll on Dev.to.
Plotting the source code “TODO” history of the most popular open source projects by Martin Schleiss.
Git Push to Remote Branch - How to Push a Local Branch to Origin by John Mosesman on freeCodeCamp.org.
Heroku-style deployments with Docker and Git tags (and post-receive hook) by Ricardo Ander-Egg Aguilar.
YubiKey for SSH, Login, 2FA, GPG and Git Signing by Marco Pivetta (Ocramius).
Diff and merge CSV files in your Git client using daff by Paul Fitz (2014).
Visual Studio code editor: Eight tips for using GitLab VS Code extension by Tomas Vik on GitLab Blog.
Top Ten Git Tips & Tricks by Julie Kent on Honeybadger blog.

Git tools and sites

Komit is a Node.js based small command line application providing interactive prompt, designed to be run as a Git hook to help follow the Conventional Commit message standard. This standard was mentioned in Git Rev News Edition #52 and #54; another tool that helps follow this standard is Sailr (also mentioned in edition #52).
Flat Data explores how to make it easy to work with data in Git and GitHub. The Flat Data project incorporates three different pieces: the Flat Action (GitHub Action), the Flat Editor VS Code extension, and the Flat Viewer website.
git-split-diffs, a Node.js command-line application, provides side-by-side split diffs with syntax highlighting in your terminal, and can be used via core.pager or pager.diff.
daff: data diff is a library and a tool for comparing tables, producing a summary of their differences, and using such a summary as a patch file. It is optimized for comparing tables that share a common origin, in other words multiple versions of the “same” table. With daff, you can also make Git diffs and merges table-aware.
github-csv-diff and CSVHub are both Chrome extensions to show CSV diffs on GitHub.
Semgrep is a fast, Open Source, static analysis tool for finding bugs and enforcing code standards at editor, commit, or CI time; rules look like the code you’re searching.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Patrick Steinhardt, Andrew Ardill, Felipe Contreras and Jonas Bernoulli.

Git Rev News Edition 74 (April 30th, 2021)

chriscool — Fri, 30 Apr 2021 11:06:51 +0000

Git Rev News: Edition 74 (April 30th, 2021)

Welcome to the 74th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of March 2021.

Discussions

Support

--no-edit not respected after conflict

Renato Botelho explained in an email to the mailing list that while he was reverting multiple commits using the --no-edit option, there was a conflict he resolved using git mergetool. After that though, the revert was not respecting the --no-edit option anymore for the next commits, so for each of them an editor was opened for him to review the commit messages.

After brian m. carlson replied to him asking for the set of commands he used or a reproduction test case, Renato provided a test case which shows that indeed after git revert --continue the --no-edit option, that was provided in the initial git revert --no-edit commit1 commit2 ... commitN command, doesn’t seem to be taken into account anymore.

Elijah Newren thanked Renato, confirmed he could reproduce the issue and said he started working on a patch that fixed the issue as well as a similar one he had found. The next day though Elijah replied to himself saying the issue turned out to be messier than expected.

He provided tables showing that the behavior (launching an editor or not) could depend on a number of factors: the command (revert or cherry-pick), the use of a terminal or not, before or after a conflict, which option (--edit, --no-edit or no option) had been passed. The tables also showed that Elijah had some doubts in some cases.

Elijah for example was not sure what should be done after a conflict when neither --edit nor --no-edit had been specified and when there was no terminal. It was not clear if an editor should be launched as it was likely to fail if there was no terminal.

Junio Hamano, the Git maintainer, replied to Elijah saying that when there is a conflict and when reverting (instead of cherry-picking), the default (that is, --no-edit is not provided) should be to give the user a chance to explain the conflict resolution or the reason for reverting in the commit message. If there is no terminal though, the process is likely automated and launching an editor might fail the operation for no good reason.

Elijah then thanked Junio, sent a proper patch to the mailing list fixing the issue and asked Renato to give it a try. Renato replied that the patch worked indeed and thanked Elijah.

Philip Oakley and Phillip Wood first replied to Elijah’s patch, which was quite complex, with only minor comments. Elijah and Junio both replied to their comments. Then Elijah sent a version 2 of his patch that only included typo fixes and comment clarifications to address Philip’s and Phillip’s suggestions.

Johannes Schindelin, alias Dscho, replied to this new version of the patch. He first said, as a tangent, that we should move away from the “Unix shell script heritage”, especially what he called “the awful let’s write out one file per setting strategy”. He would like the project to use the JSON or the INI (like Git’s own config files) format instead. He recognized that it might not be an easy switch though, as some users might unfortunately rely too much on such implementation details.

Dscho also made a number of small code suggestions. One was about how the variable encoding of the edit related options is checked. Another one was to get rid of an assert() statement that Elijah’s patch introduced. While Elijah agreed with the first one, he disagreed about the second, which started a small discussion about the value of assert() between Elijah, Junio and Dscho, with Ævar Arnfjörð Bjarmason chiming in. Elijah eventually suggested replacing the assert() statements using a new BUG_ON() macro.

About Dscho’s tangent that we should stop writing one file per setting and use a standard format instead, Elijah said he was glad talking about this because it generates a number of issues. Some of these issues are related to the different control structures and code duplication for different operations (like git cherry-pick and git rebase) because of the differences in writing the settings.

Another issue is some wasted time in the sequencer (which is used by both git cherry-pick and git rebase). There is unnecessary process forking and a lot of useless disk writing (to update the index and the working directory but also to write all the individual control files). This started a sub-thread where Dscho, Phillip Wood, Junio and Elijah discussed if it was actually necessary to often write many small files to disk. The conclusion seemed to be that we would need to check if some hooks are configured or not, so that if they are not, we can avoid writing a lot between each commit which is processed. Dscho said that “for example, if no pre-commit hook was installed that needs to be run, there was no need to update the worktree nor HEAD until the rebase is done”.

Meanwhile Elijah sent a version 3 of his patch that took into account all the suggestions Dscho had made, including the removal of the assert() statement. Dscho gave his “Reviewed-by:” and the patch has since been merged into the ‘master’ branch.

Developer Spotlight: Yann Dirson

Who are you and what do you do?

I’m Yann, and for the last few years I’ve been working on the Blade/Shadow “stream a Gaming PC” service, and currently looking for the next adventure.
What would you name your most important contribution to Git?

I can’t say that one particular thing stands out by itself. In volume I certainly contributed more to “third-party” tools: Cogito initially, then StGit (which I’m happy to see has recently received more activity and a 1.0 release), then more recently git-reintegrate. In git.git, I’ve mostly contributed small patches here and there when it itched too much, and a number of bug reports and suggestions.

What are you doing on the Git project these days, and why?

I’ve been mostly dormant there lately, and I’ve been a happy user all that time, both in dayjob and in personal projects. To me that tells a lot on the maturity of the project.

I’ve started to feel a new itch regarding git rebase -i, when iterative work requires to go back-and-forth between patches before finishing the rebase (something StGit did quite well, and possibly something most users don’t need). I only posted a PoC and some ideas a couple of weeks ago, and that’s likely to be my next venture into Git if time allows.

If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

On my first contact with Git shortly after Linus published his first version, one thing stood out for me as non-intuitive after using all those former tools: the “record only the content and not by which operation we got there” motto, which leaves to git diff the work of reconstructing the “which operation” part. Yet, soon after it struck me as probably the most brilliant aspect in Git’s design.

Today there are a handful of such operations that Git can detect, and then use when merging to make things easier: essentially renames and copies. Yet, so many other high-level operations can be made on code, and are not easy enough to merge: code restructuring inducing reindents (think Python) and symbol renaming are the first that come to mind.

This probably should be done as language-specific diff/merge tools, but those tools would likely want to share a common core. Providing such support would likely help many projects, and enable smoother workflows.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The current git rebase syntax, which feels so counter-intuitive today.
What is your favorite Git-related tool/library, outside of Git itself?

Recently the tool that has helped me most is git-reintegrate, it simplifies so much the iterative integration process with WiP branches. It still has a couple of rough edges, but as long as you don’t use submodules and don’t have to hand over the integration task to others too often, it runs really smoothly.

Releases

Git 2.31.1,
Git for Windows 2.31.1(1)
GitHub Enterprise 3.0.5, 2.22.11, 2.21.19, 3.0.4, 2.22.10, 2.21.18, 3.0.3, 2.22.9, 2.21.17
GitLab 13.11.1, 13.11, 13.10.3, 13.9.6, and 13.8.8, 13.10.2, 13.10.1, 13.9.5, and 13.8.7
Bitbucket Server 7.12
Gerrit Code Review 3.3.3, 3.2.8, 3.1.13
GitKraken 7.5.5, 7.5.4, 7.5.3
GitHub Desktop 2.7.2, 2.7.1, 2.7.0
TortoiseGit 2.12.0

Other News

Events

GitHub is announcing the Global Maintainer Summit on June 8–9th.

Various

Technology internships meet open source in Outreachy on GitLab’s blog is about recent Outreachy interns working on Git.
Enhanced Productivity with Git in Visual Studio (in upcoming version 16.10).

Light reading

Optimizing git’s merge machinery, #3 by Elijah Newren on Palantir Blog.
A look under the hood: how branches work in Git by Tobias Günther on The Overflow – the Stack Overflow blog.
Experiment on your code freely with Git worktree by Seth Kenlon (Red Hat) on Opensource.com.
5 commands to level-up your Git game: git whatchanged, git stash, git worktree, git cherry-pick and managing $HOME with Git, by Seth Kenlon (Red Hat) on Opensource.com.
A practical guide to using the git stash command by Ramakrishna Pattnaik on Opensource.com.
Scanning for secrets in Git repositories automatically, by Jake Edge on LWN.net.
How we ship code faster and safer with feature flags by Alberto Gimeno on GitHub Blog.
- Feature flags were one of solutions to hiding partial features in trunk based development, one of the patterns for managing source code branches in Martin Fowler’s article of the same name, covered in Git Rev News Edition #63 and mentioned in #73.
How to Set Up Continuous Integration for a Monorepo Using Buildkite by Subash Adhikari on freeCodeCamp.
How to Use Git and Git Workflows – a Practical Guide by John Mosesman on freeCodeCamp.
Improving shell workflows with fzf by Sebastian Jambor. The fzf tool was mentioned alongside git-fuzzy (that uses it) in Git Rev News Edition #64.
Git email flow vs GitHub flow: Comparing the GitHub and GitLab pull request workflow to the Git built-in email workflow, by Martijn Braam (2020).

Git tools and sites

posh-git is a PowerShell module which provides Git/PowerShell integration. It also provides tab completion support for common Git commands, branch names, paths, and more.

Credits

Git Rev News Edition 73 (March 27th, 2021)

chriscool — Sat, 27 Mar 2021 11:06:51 +0000

Git Rev News: Edition 73 (March 27th, 2021)

Welcome to the 73rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of February 2021.

Discussions

Support

[QUESTION] Tracking HEAD changes?

Yaron Wittenstein asked on the mailing list if there is “any possible way to track changes to HEAD using hooks”. He said he would like to listen to events such as “pre-head-checkout” and “post-head-checkout”, but thought that it was only possible using a file watch over the .git/refs directory.

Jeff King, alias Peff, first replied that he thought there was no better way, and that it was also required to watch .git/HEAD. He also showed some code for Linux/inotify he uses to automatically run tests against the current commit:
```
gitdir=$(git rev-parse --git-dir)
# We need delete_self to pick up changes to HEAD (since it gets renamed
# over), and "move" to pick up changes in the refs directories.
inotifywait -qq -t 60 -e delete_self -e move -r "$gitdir/HEAD" "$gitdir/refs"
```
Peff also recommended using Michael Haggerty’s git-test tool for avoiding re-running tests against the same commits repeatedly.

Then Peff replied to his previous email that Patrick Steinhardt also recently (since Git v2.28.0) implemented a new ref-transaction hook that can get triggered by updates to the ref that HEAD is pointing at.

Yaron replied that this seems to do the trick, except the hook doesn’t execute when switching branches. He found a work-around though by using the post-checkout hook in addition.

Peff said that he thought the hook would be triggered when HEAD is updated by a branch switch, and wondered if that was a bug, a missing feature, or something intentional in the ref-transaction hook design.

Patrick replied that the reason is that symrefs are not covered by the reference transaction mechanism itself, which existed before he implemented the new hook, and which the hook is using underneath. He also said that he should update the documentation to make it clearer what is covered by the hook and what’s not.

Yaron thanked Patrick for the clarification and asked if there were plans for the hook to be called when symrefs are updated. He also said it didn’t seem intuitive to him that the index and working dirs are being updated, which calls the “post-index-change” hook, before the transaction is approved, which in turn calls the “ref-transaction” hook.

Patrick replied that he didn’t have plan for the hook to support symrefs, but wouldn’t oppose such effort. About the order in which things were happening, he said that it is the way Git currently works and that the goal of the ref-transaction hook, which he worked on as part of his work for GitLab, was “to catch all reference updates such that one can coordinate across multiple git nodes the same action to assert they’re moving from the same state to the same state, regardless of whether they’re doing a git-push, git-merge or git-update-ref”.

Junio Hamano, the Git maintainer, further explained that “ref transaction is only about changes to the refs” and that “there is no such ‘transaction’ that treats a series of operations like object creation and index manipulation that may happen before a group of refs are updated as a single unit and make it atomic.”

Meanwhile Peff replied to Patrick’s first explanation about why symrefs are not covered by the hook saying that it might be something that could be fixed. He also said that GitHub’s custom repository replication mechanism does track symref updates, but uses a simple lock mechanism to get the state of the symrefs, while it uses a 3-phase commit based on custom code similar to the ref-transaction hook for normal refs.

Yaron then summarized his understanding of how things work and asked if he was right. Peff replied that it matched his understanding.

Releases

Git 2.31.0, 2.31.0-rc2, 2.30.2 and below for CVE-2021-21300, 2.31.0-rc1, 2.31.0-rc0
Git for Windows 2.31.0(1), 2.31.0-rc2(1), 2.31.0-rc1(1), 2.31.0-rc0(1), 2.30.2(1)
Bitbucket Server 7.11
GitHub Enterprise 3.0.2, 2.22.8, 2.21.16, 3.0.1, 2.22.7, 2.21.15, 2.20.24
GitLab 13.10, 13.9.4, 13.8.6, and 13.7.9, 13.9.3, 13.9.2, 13.8.5 and 13.7.8, 13.9.1
GitKraken 7.5.2
GitHub Desktop 2.6.6, 2.6.5, 2.6.4

Other News

Various

Git clone vulnerability announced by Taylor Blau on GitHub Blog, and A vulnerability in Git by Jake Edge on LWN.net.
Highlights from Git 2.31 by Taylor Blau on GitHub Blog.
Congratulations to Joey Salazar and Charvi Mendiratta who successfully completed their Outreachy internship working on Git!

Light reading

Optimizing git’s merge machinery, #1 and #2 by Elijah Newren on Palantir Blog.
How Does Git Work? by Julie Kent.
Git is my buddy: Effective Git as a solo developer by Mikkel Paulson.
How to Utilize Submodules within Git Repos: One Solution When the Primary Code Can be Open Source, but Specific Content Needs to be Private, by Paige Niedringhaus on Bits and Pieces blog (a Medium site).
How to use .mailmap file in git repository by Lukáš Mešťan (2020).
What is Trunk Based Development? A Different Approach to the Software Development Lifecycle by Kealan Parr on freeCodeCamp. This approach was also one of those described in Patterns for Managing Source Code Branches by Martin Fowler, which was mentioned in Git Rev News Edition #63.
Improving large monorepo performance on GitHub by Scott Arbeit on GitHub Blog, in the Engineering section.
Hacking the git shell prompt by Mark Dominus describes a hack creating a generic mechanism for abbreviating or transforming the branch name in the prompt.
Boost Your Programming Skills by Reading Git’s Code by Jacob Stopak on freeCodeCamp.
How To Set Up Continuous Integration With Git and Jenkins by Suparna Khamaru on LambdaTest Blog.
Store your Kubernetes Secrets in Git thanks to Kubeseal. Hello SealedSecret! by Aurélie Vache on Dev.to. More generic solutions for storing secrets in Git repository were described in Git Rev News editions #39 and #57, among others.

Git tools and sites

Project GITenberg is a Free and Open, Collaborative, Trackable and Scriptable digital library. It leverages the power of the Git version control system and the collaborative potential of GitHub to make books more open. The books in this project originate from the work of Project Gutenberg, a volunteer effort to digitize and archive cultural works, mostly the full texts of public domain books.
ungit is a Git command-line UI with text editor integrations, that utilizes your web browser as graphical interface. It is intended to make Git easier to use. In this it is somewhat similar to no longer actively developed Easy Git.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Ævar Arnfjörð Bjarmason and Matheus Tavares Bernardino.

Git Rev News Edition 72 (February 27th, 2021)

chriscool — Sat, 27 Feb 2021 11:06:51 +0000

Git Rev News: Edition 72 (February 27th, 2021)

Welcome to the 72nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of January 2021.

Discussions

Reviews

[PATCH 0/5] Support for commits signed by multiple algorithms

brian m. carlson sent a patch series to allow verifying signed commits and tags when using multiple hash algorithms. This is a follow up from brian’s multi-year work on supporting the SHA-256 hash algorithm in Git, to deal with the fact that the original SHA-1 algorithm is becoming more and more outdated and insecure.

One of the trickiest part in supporting a new hash algorithm is that when Git objects (except blobs) are converted to the new hash, their contents changes, because the hashes they contain (to reference other Git objects) are converted too. So old signatures they contain become invalid.

A way to overcome this issue is to add a new signature, that signs the converted object, to each signed object that is converted. This way such object would have 2 signatures, and can always be verified using one of them, even if it gets converted back and forth.

brian’s patch series addressed the issue that for SHA-256 tags it was initially planned to have the signature in a Git object header (which is called a header signature) instead of at the end of the tag message (which is called a trailing signature), but unfortunately the patch implementing that got lost. So we use trailing signatures.

brian then explained “We can’t change this now, because otherwise it would be ambiguous whether the trailing signature on a SHA-256 object was for the SHA-256 contents or whether the contents were a rewritten SHA-1 object with no SHA-256 signature at all.” So the solution he implemented was to “use the trailing signature for the preferred hash algorithm and use a header for the other variant”.

brian thinks this solution is the best we can do in the current situation, as it still allows converting back and forth between hashes, and verifying signatures created with older versions of Git, though tags signed with multiple algorithms can’t be verified with older versions of Git.

For commits, brian’s patch series fixes the bug that old header signatures weren’t stripped off before verifying new signatures, so verification always failed.

The result of his series is then that signing both commits and tags can now be round-tripped through both SHA-1 and SHA-256 conversions.

Junio Hamano, the Git maintainer, replied to a patch in the series suggesting using the size_t type for byte lengths, instead of unsigned long, as unsigned long was breaking 32-bit builds.

brian agreed and sent a version 2 of the series with Junio’s fix.

Junio replied to the cover letter of this series asking “How widely are SHA-256 tags in use in the real world, though?”, and if it was really too late to use a header signature for tags, as was originally planned.

brian replied:

I don’t know. I don’t know of any major hosting platform that supports them, but of course many people may be using them independently on self-hosted instances.

He also explained why he thought the solution didn’t matter much, because he’d just noticed that old Git versions don’t properly strip header signatures, so wouldn’t anyway be able to verify tags or commits with multiple signatures.

He ended his reply saying “there’s a lot more prep work (surprise) before we get to anything interesting.” To which Junio replied: “Uncomfortably excited to hear this ;-)”.

brian replied with an interesting summary of his in progress work.

Gábor Szeder then reported a Clang warning, while Junio suggested more unsigned long to size_t changes.

brian then sent a version 3 of his patch series with fixes for the issues reported by Gábor and Junio, and then a few weeks later version 4 to fix another small issue.

This patch series is scheduled to be merged in the master branch soon.

Developer Spotlight: Taylor Blau

Who are you and what do you do?

I am Taylor. I work at GitHub, where I spend most of my time contributing to the Git project.
What would you name your most important contribution to Git?

I’m still submitting many of the patches, but I think multi-pack reachability bitmaps will be my most important contribution to Git so far.

If they work, they’ll allow hosting providers who rely on reachability bitmaps more flexibility to control when and how they repack their repository. If you want to use bitmaps, you have no choice but to repack your repository into one enormous pack. Multi-pack reachability bitmaps mean that you won’t have to, and can instead repack your repository however you want.

If I’m limited to things that I have finished, I would say that the on-disk reverse index is another good one. But that’s kind of cheating, since it’s related to multi-pack bitmaps ;).
What are you doing on the Git project these days, and why?

Most of my time is spent working on multi-pack bitmaps. There are a lot of different topics in my fork that all need to get merged in order to make this feature work. So, I’m spending my time in all of the usual ways: submitting patches, responding to review, submitting more patches, and so on.

When I’m not doing that, I enjoy to read and review patches from other folks on the list. I feel like there is a lot of exciting work going on recently, and so I’m always interested.

Every release or so I have the pleasure of writing a “release highlights” blog post that GitHub publishes. We’re still a few weeks away from a release (at the time of writing), so it’s not something that I’m working on yet, but it will come up soon enough.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I’m not sure :). I care a lot about performance on large repositories, so I think that if I were in charge of such a team, that I would just set them loose to explore the boundaries of what’s possible, and push them further.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Gosh, I would love to get rid of .keep packs, or at least the distinction between in-core and on-disk ones. They’re incredibly useful, but they are subtly different, in ways that are sort of hard to reason about.
What is your favorite Git-related tool/library, outside of Git itself?

I use tig often, particularly its blame and log view. Michael Haggerty’s git when-merged is another indispensable tool in my workflow.

I’m curious to try Stephen Jung’s git absorb tool, but I haven’t gotten to it yet.

Releases

Git 2.30.1
Git for Windows 2.30.1(1)
GitLab 13.9, 13.8.4, 13.7.7 and 13.6.7, 13.8.3, 13.8.2, 13.7.6 and 13.6.6, 13.8.1, 13.7.5
Bitbucket Server 7.10
Gerrit Code Review 3.3.2, 3.2.7, 3.1.12, 3.0.16, 2.16.27, 2.15.22
GitKraken 7.5.1
GitHub Desktop 2.6.3

Other News

Various

At FOSDEM 2021 (this year the event happened in a virtual format) there was a lightning talk Building a Git learning game: A playful approach to version control (video available) initiated by two students who wanted to understand Git themselves… This Oh My Git! game is Open Source and written using the Godot game engine. There are binaries for Linux, macOS, and Windows, but currently no web version, as the game uses real Git as a part of its backend (with some sandboxing).

The similar interactive online Learn Git Branching game was mentioned in Git Rev News Edition #30.

Light reading

In Getting The Most Out Of Git article in Smashing Magazine, the author Tobias Günther explores some of the less known but very useful features in Git: how to recover deleted commits, clean up your commit history, use submodules to manage third-party code and compose commits with precision.
How to Use Branches in Git – the Ultimate Cheatsheet by Tobias Günther on freeCodeCamp describes how to create, rename, switch, publish, track, delete, merge, rebase and compare branches.
How to Collaborate on Data Science Projects with DAGsHub (and DVC (Data Version Control)), by Linda Ikechukwu on freeCodeCamp. DVC was first mentioned in Git Rev News Edition #42.
The RefinementCodeReview post by Martin Fowler describes an alternative to the PullRequest mechanism for code review, namely one that is triggered each time the code is looked at rather than when the code is added to the codebase.
In Monorepos Chris Coyier explains the reasoning, pros and cons for them, moving back toward a monorepo at CodePen. You can find links to articles advocating for and against monorepos, among others, in Git Rev News Edition #47.
Rewriting your git history, removing files permanently - cheatsheet & guide by Don Goodman-Wilson on GitGuardian blog.
2020 Version control best practices: Five easy ways to enhance team collaboration (PDF) – a booklet by GitLab.

Git tools and sites

DAGsHub Storage is an alternative (and free-to-use) DVC remote that requires zero configuration.
Commitizen is an Open Source project that helps contributors be good Open Source citizens. It accomplishes this by prompting them to follow commit message conventions at commit time, asking the user fill in any required fields and automatically formatting the commit message according to selected convention.
Git Gud by Ben Thayer is a command line game designed to help you learn how to use Git. Note that there was a pretty barebone visual web-based Git simulator with the same name by Nic Hartley, which got mentioned in Git Rev News Edition #48, but it is no longer available.

Credits

Git Rev News Edition 71 (January 28th, 2021)

chriscool — Thu, 28 Jan 2021 11:06:51 +0000

Git Rev News: Edition 71 (January 28th, 2021)

Welcome to the 71st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of December 2020.

Discussions

Reviews

[PATCH 00/26] git-log: implement new –diff-merge options

Last November Sergey Organov sent a 26 patch long series to the mailing list. This series added a number of new modes to git log --diff-merges=<mode>.

Before this patch series, there would be no diff for merge commits unless one of -m, -c or --cc was given. And in case one of these options was given, then --diff-merges=off, or its --no-diff-merges synonym, could be used to remove that diff output for merge commits. This was the only possible use of --diff-merges=<mode>.

Sergey’s patch series introduced four new modes. Three of them, “separate”, “combined” and “dense-combined” do not generate new diff output. They are just synonyms of -m, -c and --cc respectively.

The fourth new mode, called “first-parent”, though allows to get the same output as -p --first-parent, but “without the changes in history traversal that the --first-parent option causes”.

Sergey’s patch series also refactored some code and fixed a small issue. In a follow up email Sergey asked questions related to further possible issues related to how -m, -c and --cc interact with --oneline.

Elijah Newren replied to Sergey’s questions, and a long discussion involving Junio Hamano, the Git maintainer, started about different technical topics, especially the interactions between -p and the -m, -c and --cc options.

Elijah and Philip Oakley also commented on small issues in a few patches.

Sergey then sent a new version, that he named v1, of his patch series with 27 patches, so one more than in the original series. The changes were mostly typo and documentation fixes.

Elijah and Junio commented on the patch series. Elijah and Sergey discussed some new --remerge-diff and --remerge-diff-only options Elijah had been working on, and how there could also be a related --diff-merges=remerge mode.

Junio found a few issues and suggested some renaming and test improvements.

Sergey sent a new v2 version of his patch series with 33 patches, so 6 more than in v1. One change compared to the previous version was that the diff output for the new --diff-merges options didn’t affect non-merge commits. Another change was that short mnemonics --diff-merges=(1|m|c|cc) were provided on top of long mode names. A lot of smaller changes addressed Elijah’s and Junio’s reviews.

Elijah and Sergey then discussed further improvements especially to the documentation. Felipe Contreras and Junio sometimes also chimed in with further explanations or suggestions.

Sergey sent a new v3 version, with 32 patches, one less than in v2. The changes were mostly following reviewers’ suggestions. Felipe commented positively on one patch, and Junio said he didn’t spot anything objectionable in the series and was OK to start merging it to the next branch.

Developer Spotlight: Sergey Organov

Who are you and what do you do?

I’m a software engineer and system architect at JAVAD GNSS, working in their Moscow Research Center, in Russia. We design (and manufacture) high-end GNSS receivers, both hardware and software. Design and implementation of receiver firmware is my primary job for about 25 years already. I’m also responsible for the development tools our team is using, and that’s where GNU/Linux and then Git come to the picture.

Graduated from “Moscow Engineering Physics Institute” back in 1989 and qualified in “Experimental Methods in Nuclear Physics”, I was always interested in computing. I then worked for about 10 years in “Kurchatov Institute” in the field of computer modeling of nuclear radiation and detectors, as well as in advanced processing of experimental results. Then, a few years later, I started to work for JAVAD as well, in parallel. A few more years later, I left Kurchatov and entirely focused on working for JAVAD full-time, which is my current job.

Real-time embedded applications, also using Linux on the targets, is my primary field of expertise nowadays.
What would you name your most important contribution to Git?

I didn’t contribute much. I’d name the method of rebasing of merge commits, that has been covered in the Git Rev News some time ago, as the most important one.
What are you doing on the Git project these days, and why?

Right now I’m working on --diff-merges options for git log. The original stimulus was very surprising output of git log -p -m that made me mad the first time I encountered it. After finishing initial implementation of the --diff-merges options, I now aim at finally giving git log -m natural meaning of printing the diff for merge commits with respect to the first parent only.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Actually, I have 2 favorites:
1. Designing support for explicit commits grouping, somewhat similar to grouping objects in graphical editors, likely implemented as a container commit capturing a particular part of the DAG. It’d be then seen as a single commit by default, unless the user specifically asks to look inside. If we had it, our typical history would be more linear, feature branches essentially becoming single (group) commits, that’d make history simpler to traverse and to reason about.
  
  Right now the only poor-man approximation for that is a branch that is merged back to its origin (the true-non-evil merge, as I call it), which results in a history that looks like a sequence of bubbles, but it lacks direct support which the specific grouping feature would have.
2. Designing a new history editor that will aim at being the ultimate replacement for both git rebase and git cherry-pick, which are essentially the same thing at fundamental level. As useful as these existing features are, they have wide opportunities for improvements that apparently don’t fit into the current design, and their history of incremental adaptations to different needs made quite a mess of them.
  
  Covering all the functionality of rebase and cherry-pick, the two most important new features I’d like to see are:
  - Ensuring, by design, one of the primary features of any reasonable editing tool: carefully preserve the content if no actual editing has been made or requested. This should be ensured even if the tool is forced to do the full job of re-creating the history according to the instructions. I.e., the cycle: load/mark-as-modified/save should result in the original result by default.
  - Better replacement for to-do lists. Carefully designed format for describing the DAG in a text form convenient for humans and for editing with a text editor, with simple yet strictly defined syntax and semantics, preferably supporting generic programming language features. For example, it could be based on some existing language, say, Tcl. Yet it should take the best features of the current format and look familiar enough to be immediately useful without a significant learning cycle.
[That said, do we need two teams of expert developers for that, or one would suffice, I wonder?]
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Support for octopus merges. Multiple (back) references could then be reused for more useful things, like keeping history of rebasing, and/or for commits grouping (see above).
If you could add something to Git without worrying about backwards compatibility, what would it be?

I’d add a simple model behind the Git command-line options, so that their design came from the model rather than entirely from the use cases, as it happens to be now. It’d play a similar positive role in UI design as the Git core data model plays in the features design.

Then, I sometimes think about the addition of a single NULL-commit, the ultimate parent of all the Git commits all over the world. I’m not sure it has enough value in simplifying corner cases in Git’s implementation, but it fits so nice into the elegant Git data model!
What is your favorite Git-related tool/library, outside of Git itself?

Emacs and the Magit, its interface to Git, in particular, as well as a few parts of Emacs generic VC interface that features Git among others. The Magit got to the point already where I rarely find myself using the Git command-line directly, and then mostly for some batch-processing, or on hosts where Emacs is not readily available.

Releases

Git 2.30.0
Git for Windows 2.30.0(2), 2.30.0(1)
GitHub Enterprise 3.0.0
GitLab 13.8 13.7.4, 13.6.5 and 13.5.7, 13.7.3, 13.7.2, 13.6.4, and 13.5.6
Bitbucket Server 7.9
Gerrit Code Review 3.3.1, 3.2.6, 3.1.11
GitKraken 7.5.0
GitHub Desktop 2.6.2

Other News

Various

Meet Praefect: The traffic manager making your Git data highly available: How GitLab scales Git and makes it highly available.
Git your updates now: Version control system hits 2.30, preps for main switch by Julia Schmidt.

Light reading

Git clone: a data-driven study on cloning behaviors by Solmaz Abbaspoursani on GitHub blog continues where Derrick Stolee’s article on git clone options, mentioned in the previous edition, left off.
Git Metadata Cloning - Learn about the performance impacts of cloning repository metadata.
MAINTAINERS truth and fiction article by Jonathan Corbet on LWN.net describes how one can analyze Git history of the Linux kernel for insights to be gleaned from comparing MAINTAINERS entries against activity in the real world.
How to Use Multiple Git Configs on One Computer with the help of includeIf directive, by Dhruv Barochiya on freeCodeCamp.
Keeping Git Commit Messages Consistent with a Custom Template by Timothy Merritt on DEV.to.
Conflict resolution in various mergetools by Seth House was previously an appeal to mergetools authors to stop doing three-way merges from scratch, but now describes the effect of patches by Felipe Contreras and several other people that changed the default behaviour of git mergetool (this can be controlled with the new mergetool.autoMerge and mergetool.<tool>.autoMerge config options).
10 things to love about Git by Joshua Allen Holm lists OpenSource.com readers’ favorite Git articles of the year 2020.

Git tools and sites

code-compass is a package that is intended to guide you in your software development within Emacs. For example, you can let history show you which files to edit next or examine how files are historically related to each other.
Crev is a Scalable, social, Code REView and recommendation system (rather than change review system); currently Crev for Rust/cargo is ready and working.

Credits

Git Rev News Edition 70 (December 26th, 2020)

chriscool — Sat, 26 Dec 2020 11:06:51 +0000

Git Rev News: Edition 70 (December 26th, 2020)

Welcome to the 70th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of November 2020.

Discussions

General

Three Outreachy interns have been accepted to work on Git this winter:
- Sangeeta from India will be mentored by Kaartic Sivaraam and Christian Couder to work on the ‘Accelerate rename detection and the “range-diff” command in Git’ project. Sangeeta started blogging about her internship.
- Joey Salazar from Costa Rica will be mentored by Emily Shaffer and Jonathan Nieder to work on the ‘Add Git protocol support to Wireshark’ project. Joey also started blogging.
- Charvi Mendiratta from Faridabad, Haryana, India will be mentored by Phillip Wood and Christian Couder to work on on the ‘Improve dropping and rewording commits in Git interactive rebase’ project. Charvi also started blogging.

Reviews

[PATCH 00/10] Advertise trace2 SID in protocol capabilities

Last October Josh Steadmon sent a patch series to the mailing list. The goal of the patch series was to allow a Git client and a Git server, that are communicating to perform a Git operation like a push, a fetch or a clone, to share each other’s trace2 session ID (SID).

Trace2 is a relatively new tracing mechanism that was developed primarily by Jeff Hostetler to improve on the previous trace mechanism.

These tracing mechanisms let users print debug, performance, and telemetry logs to a file or a file descriptor, so that they can better understand what’s going on inside Git processes.

Josh’s patch series allows a Git client to record the server’s trace2 session ID in its logs, and vice versa, by advertising the session ID in a new “trace2-sid” protocol capability.

Josh asked 2 questions in the cover letter of his patch series though. He first asked if the code in the trace2/ directory was supposed to contain only implementation details hidden from the rest of Git and accessible only through the trace2.h and trace2.c files. The reason for this question is that Josh’s code needed to access the trace2 session ID which was previously managed only in trace2/tr2_sid.h and trace2/tr2_sid.c.

Josh’s second question was if it was OK to add a trace2.announceSID configuration option for the feature his patch series implemented. The reason is that some Git processes on servers, like git upload-pack, have previously been prevented to read some potentially malicious config options from local repositories for security reasons.

Jeff Hostetler was very happy with Josh’s patch series saying “Very nice! This should be very helpful when matching up client and server commands.”

He also replied that he indeed intended the trace2/ directory to be opaque, so “that just trace2.h contains the official API”. And he suggested adding a new trace2_session_id() function to trace2.h and trace2.c, that would just call the existing tr2_sid_get() function from trace2/tr2_sid.h and trace2/tr2_sid.c.

Jeff also pointed to the fact that the session ID of a process was built up based on the session IDs of its parent processes. For example a Git process spawned from another Git process will have a session ID of the form <sid1>/<sid2>, where <sid1> is the session ID of its parent. And if it spawns another Git process, the session ID of this new process will be of the form <sid1>/<sid2>/<sid3>.

Jeff also mentioned that if the GIT_TRACE2_PARENT_SID environment variable, which is used to communicate the session ID of the parent process, already contains something, for example ‘hello’, when the initial Git process is launched, then the session IDs will accumulate after this existing content, like hello/<sid1>/<sid2>/<sid3>.

Jeff wondered if clients and servers should share only the last session ID component, for example <sid3>, instead of the full session ID.

While Jeff couldn’t answer Josh’s second question about possible security issues with using a new trace2.announceSID configuration option, Junio Hamano, the Git maintainer, replied that it was probably OK, given the fact that Git processes, like git upload-pack, already take into account at least some boolean config options, like uploadpack.allowrefinwant.

Josh thanked Jeff for his review, and said that in the version 2 of his patch series he had implemented the new trace2_session_id() function in trace2.h and trace2.c Jeff had suggested, and that it was probably OK for clients and servers to share their full session ID rather than the last component.

Junio asked Josh to document this design decision to share the full session ID. Josh replied to Junio that he did that in the version 3 of his patch series.

In reply to version 2 of the patch series though, Junio had also requested that session IDs, how they look like, and what special characters they can contain, should be better documented to help third parties writing their own implementation of the protocol.

This spawned a small discussion thread where Jeff, Ævar Arnfjörð Bjarmason, Junio and Josh eventually agreed on limiting the content of the GIT_TRACE2_PARENT_SID environment variable and session ID to printable, non-whitespace characters that fit into a Git protocol line.

Another discussion following version 2 between Josh, Junio and Johannes Schindelin, alias Dscho, was about Junio’s suggestion to separate the concept of “session” from the trace2 mechanism. This led to the decision to use just “session ID”, instead of “trace2 session ID”, in the documentation, and to call the new configuration option transport.advertiseSID instead of trace2.announceSID.

Other smaller discussions over details of the implementation and the documentation followed version 2, but version 3 got merged into the next and then the master branch. So this new feature will be released in soon upcoming Git v2.30.

Developer Spotlight: Felipe Contreras

Who are you and what do you do?

I’m a software engineer who has worked in all areas of software development. These days they use the term “full stack developer” for a developer that works on all areas of web development, which I have done, but I’ve also worked on Linux kernel development, middleware, UI; you name it.

Right now I’m a freelancer offering services to local companies doing mostly web development, but not quite.

It’s hard to pigeonhole me because I not only do software development, I also write a blog (which is not only about software), I’ve moderated online communities, and I read a lot from intellectuals regarding the ongoing culture war, and so on.

I guess you could say I’m a jack of all trades (but I’ve actually mastered a few).
What would you name your most important contribution to Git?

That’s very hard to tell because I’ve worked all over the place, so most of my changes are minor improvements. But I guess the one with the biggest impact to users would have to be git-remote-hg; a bidirectional bridge between Git and Mercurial.

Ironically I’ve never had to use Mercurial, nor worked on a project that uses Mercurial. However, I did work on projects that used Subversion and CVS back in 2005, when Git started, and I found it useful that there existed tools to use Git while working with other version control systems.

I used to contribute to Pidgin (the MSN protocol parts), which used Monotone, and I refused to work on such a horrendous VCS, so I started to work on scripts to convert Monotone repositories to Git, and I contributed my patches back through Bugzilla (like all other contributors).

This gave me insight into the inner workings of Git, and eventually when the Pidgin project decided to move to Mercurial (an obvious mistake in my opinion), I started surveying the tools to convert from Git to Mercurial, and I found lots of areas of improvement.

Regarding these tools I would be remiss if I didn’t give attribution to Rocco Rutte, who created the first fast-export script, which I used as inspiration for git-remote-hg, but unfortunately died of cancer in 2009. Without his work I might not have started this particular journey.

Using Rocco Rutte’s program, I had the idea to take that approach, but hide it inside Git’s remote-helper infrastructure, which was surprisingly easy. Everything else that came after was fine-tuning, adding features, and improving Git’s infrastructure to make such features possible.

In response to some pushback that I received from more established Git developers – who claimed that some of these changes were specific to git-remote-hg – I decided to create git-remote-bzr as a proof of concept to interact with Bazaar (again, I never personally had to use Bazaar), but it turned out there was a huge demand for such a tool, so I kept working on it.

Some GNU Emacs developers loved git-remote-bzr, and it probably helped in the eventual move to Git, even though Richard Stallman initially pushed back hard against it.

So, even though I never really used git-remote-hg or git-remote-bzr, I kept working at them because clearly other people did. I understand all too well the frustration of working on a VCS that is foreign and suboptimal, especially when you know Git has everything you need; it’s like being stranded.
What are you doing on the Git project these days, and why?

A lot of things. I stopped working on the Git project for many years, but right now I have motivation to work on it again, and there’s literally dozens of features I’m working on. Unfortunately my patches have a tendency to not be accepted, so many of these will not end up helping the end users, but I’m thinking of ways to make these available outside of Git.

The main one is improvements to git pull. Initially there was a complaint from a Red Hat employee about an annoying warning added recently, which prompted me to look back at work I did in 2013 which solves all this, but was never merged. Back then the git pull code was written in shell script, now it’s in C, so I had to rewrite all this functionality.

It’s a lot of work because there are many different workflows, configurations, and options that affect the way git pull works. I think the bulk of the code is mostly done, but there’s a few options I would like to explore that I haven’t mentioned yet in the mailing list, since the current patch series is controversial as it is.

Part of the work is reading back old mail threads which go back to 2008. A lot of problems and suggestions have been mentioned throughout the years, and my patch series tries to compile all of those, in addition to the comments from 2020.

The story of these changes is interesting enough that I have been writing a blog post about it, which is going to be enormous, but a lot more work is needed to finish it properly. Hopefully it will be ready for the next edition of Git Rev News.

In another irony; I don’t even use git pull (I use git fetch + git merge / git rebase).
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I would split Git into a library and a command line interface.

Clearly there’s a need for a stand-alone library, since there is libgit2, but Git doesn’t use libgit2, so one has to always catch up with the other.

Recently Ævar Arnfjörð Bjarmason mentioned a thought about somehow splitting the porcelain and plumbing of Git; the part that is for typical end users, and the part that is for advanced users or scripts. Splitting the command line from the library would allow us to more easily see what part belongs where. Plus, I would split the command line into two; git and git-tool. The git command should be for typical end users, and the documentation about those commands should not include any implementation details, or plumbing.

I believe having a clean command line, which hides implementation details and plumbing, would be of great benefit to the average Git user, and in addition would help developers visualize what changes are more likely to affect the end user, plus where the focus of improving documentation should be.

Oh, and one person on the team should be not a developer, but a copy editor, and his job would be to rewrite all the documentation. It’s probably incontrovertible that Git’s documentation can be improved a lot.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I don’t think I would remove anything from Git.

Plus, I don’t believe any good developer should stop worrying about backwards compatibility, ever. I’m of the opinion that there’s always a way to implement changes that are incompatible with previous versions, but there’s a series of steps. First you add the new functionality, then you add a deprecation period, then you make the new functionality the default, but always allowing the user to access the old functionality.

It’s a lot more work, and takes a lot more time, which is why many bad projects don’t do it, but I think you always need to worry about backwards compatibility, and it’s a good thing Git developers do worry about that.

OK, maybe merge.defaultToUpstream, nobody uses that.
What is your favorite Git-related tool/library, outside of Git itself?

I don’t really use anything outside of Git.

I find Git vanilla to be mostly good enough to do everything I need; and when I don’t, I try to introduce that directly into Git itself.

I created a fork of Git called git-fc with all the features I didn’t manage to land into Git upstream, but I have not updated it in some years (it’s in my endless to-do list), and even though I miss those features a lot, I can manage.

I also have a bunch of projects that add other functionality, like git-related, git-reintegrate, and git-send-series, but I could live fine without those.

I think the only tool I would find very hard to live without is git-smartlist. Since I use gitk a lot to visualize commit history, very often I just want to see the history from the master branch to the current branch I’m at, and while usually you can do that with master..@, that’s not always the case and git smartlist helps a lot in telling gitk exactly what I want to see.
Outside of code, is there anything you would like to change about the Git project?

I think there’s a disconnection between users and developers. Recently I’ve been talking about the curse of knowledge; the better you know something, the less you remember about how hard it was to learn. It’s very typical for experts to underestimate how hard it is to understand something, because they’ve had many years of experience with it.

One example is rebasing. Basically all Git developers are very familiar with rebasing, so they can’t imagine what it must be like for a user to not know how to rebase, or worse; to not know what a rebase is. But feedback from people whose job is to train users tells us the vast majority of new users have no idea what a rebase is.

Of course the Git developers care about the users, but many times we have to imagine hypothetical users and their needs, and it’s not rare that these don’t match the needs of real users.

That’s why Git Users’ Surveys are so important. Unfortunately they haven’t been made in many years, and to be honest I don’t see much point in them if the developers are not going to trust the results and use them to guide the project.

In all the users’ surveys the number one and two areas of improvement without fail are: user-interface, and documentation, and I believe those are the two areas that are neglected the most.

I would take this feedback seriously, and as a project make a real effort to try to improve in these areas.

Releases

Git 2.30.0-rc2, 2.30.0-rc1, 2.30.0-rc0
Git for Windows 2.30.0-rc2(1), 2.30.0-rc1(1), 2.30.0-rc0(1), 2.29.2(3)
Gerrit Code Review 3.3.0
GitHub Enterprise 2.22.6, 2.21.14, 2.20.23, 2.22.5, 2.21.13, 2.20.22
GitLab 13.7.1, 13.7, 13.6.3 13.6.2
GitKraken 7.4.1
GitHub Desktop 2.6.1

Other News

Various

Felipe Contreras shared his sharness/test Vim syntax file to the list. It enables syntax highlighting for the body of test_success, test_failure etc.

Light reading

Use the Git History to Identify Pain Points in Any Project “basic idea - files that change often (with some exceptions) tend to be the ones where most issues occur” - let’s go find them with this useful command. Includes a useful follow on reading about your code crimes.
Commits are snapshots, not diffs by Derrick Stolee on GitHub Blog.
Get up to speed with partial clone and shallow clone by Derrick Stolee on GitHub Blog.
Optimize your monorepo experience - GitHub Universe 2020: video of presentation by Derrick Stolee, Staff Software Engineer, GitHub.
The Philosophy of Scalar, a part of Scalar docs; the tool itself, intended to provide settings and extensions for Git to help manage large Git repositories, was introduced in Git Rev News #60 and further mentioned in Git Rev News #61.
How to Make Your Code Reviewer Fall in Love with You by Michael Lynch; a good counterpart to The Gentle Art Of Patch Review by Sage Sharp from 2014.
8 Git aliases that make me more efficient by Ricardo Gerardi on Opensource.com. Use aliases to create shortcuts for your most-used or complex Git commands.
10 Git Anti Patterns You Should be Aware of, slide deck presented by Lemi Orhan Ergin at ITAKE UnConf 2018; though one should take it and especially the proposed solutions with a critical eye.
Regular Expression Matching with a Trigram Index, or How Google Code Search Worked by Russ Cox (2012).

Git tools and sites

Radicle intends to be a peer-to-peer stack for building software together, based on Git and Radicle Link peer-to-peer protocol.
Compare with ForgeFed (formerly GitPub), a federation protocol for software forges, mentioned in previous Git Rev News.
git-smartlist by Felipe Contreras; a tool to help create typical revisions (e.g. master..@) by generic name, so that you don’t have to.

Credits

Git Rev News Edition 69 (November 27th, 2020)

chriscool — Fri, 27 Nov 2020 11:06:51 +0000

Git Rev News: Edition 69 (November 27th, 2020)

Welcome to the 69th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the About Git Rev News page on git.github.io.

This edition covers what happened during the month of October 2020.

Discussions

Reviews

[PATCH] userdiff: support Bash

Victor Engmark sent a patch to add support for Bash and POSIX shell to the userdiff mechanism. This mechanism is used by the diff code to make diffs more informative and better suited to the content, in this case Bash or POSIX shell programs.

As explained in the documentation, diffs contain sections called hunks that look like:
```
@@ -k,l +n,m @@ TEXT
```
where k, l, n and m are numbers indicating the lines that are concerned, and TEXT, which is called the “hunk-header”, is a part of a line of the file to further help identify the related context of the diff in the file.

The best thing for programs is often to have the name of the enclosing function, or method, in the hunk-header. As detecting functions is programming language specific, it’s the role of the userdiff mechanism to provide a regex (regular expression) that can be used to do that.

Another role of the userdiff mechanism is to provide a regex to customize word diffs.

Victor’s patch then mainly consisted in adding regexes for Bash and POSIX shells to userdiff.c, along with some documentation and a lot of tests.

Junio Hamano, the Git maintainer, replied to Victor, by commenting a bit on the tests and a lot on the complex regex to detect a function. He wondered if it correctly accepts white spaces where they are allowed, and suggested for more clarity to break it down like this:
```
"^[ \t]*"                    /* (op) leading indent */
"("                          /* here comes the whole thing */
"(function[ \t]+)?"          /* (op) noiseword "function" */
"[a-zA-Z_][a-zA-Z0-9_]*"     /* identifier - function name */
"[ \t]*(\$[ \t]*\$)?"      /* (op) start of func () */
"[ \t]*(\\{|\\(\\(?|\\[\\[)" /* various "opening" of body */
")",
```
Victor then sent a version 2 of his patch implementing Junio’s suggestions and answering his comments.

Johannes Sixt then suggested a number of improvements especially about the tests, and about the regex to customize word diffs. Victor replied about the latter asking for pointers to look at, as it seemed that there were no tests for that.

Victor nevertheless sent a version 3 implementing Johannes’ suggestions, and Johannes indeed replied that he was happy with the result. Junio was also happy with the result after fixing a typo in the commit message.

The patch was later merged to the next and then master branches, so Git should soon support shell scripts in a better way, while it itself has been developed for a long time using shell scripts.

Developer Spotlight: Philippe Blain

Who are you and what do you do?

I’m a scientist at the Canadian Center for Meteorological and Environmental Prediction, in Montréal, Québec, Canada. I’m part of the development team for the numerical model we use to predict the movement, growth and melt of sea-ice, the frozen parts of the Arctic and Antarctic oceans. Like most computer models in the field of weather forecasting, this software is written in good old Fortran, and runs on our supercomputers. We use Git extensively to track changes across all layers of our technological stack, and I quickly developed an interest in Git’s inner workings.
What would you name your most important contribution to Git?

Since I started contributing to the project a little more than one year ago, I’ve mostly been trying to fix the bugs I encounter in the course of my daily work. So I’m not sure which one of my topics has had the biggest impact on other users. However, I can say that the contribution I’m most proud of is fixing git checkout --recurse-submodules to correctly switch between branches when one branch has nested submodules and the other branch has no submodules at all. I learned enormously during the process of developing this fix, not only about how Git “unpack trees” to keep the index, working directory and HEAD consistent, but also how fork and exec calls work and especially how to debug such spawned processes using GDB and LLDB.
What are you doing on the Git project these days, and why?

Right now I’m working on a fix to prevent git checkout --recurse-submodules from losing uncommitted work in submodules. Although the documentation says this shouldn’t happen, I’ve found a few cases where it does, and since it’s never a nice experience to lose work, I’d like to fix that.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Apart from rewriting the whole thing in C++, you mean? Jokes aside, I would like for more work to be put towards better submodule support. There was a colossal effort a couple of years ago to add --recurse-submodules flags to several Git commands, so that submodules worktrees stay up to date when switching between superproject commits. Unfortunately this effort has died off due to core contributors to the submodule code changing jobs, and some porcelain commands still lack that capability.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I think it’s unfortunate that the dot-dot vs. dot-dot-dot syntax mean different things in git diff than in the rest of Git commands. It’s another one of those tricky things that users have to remember. The fact that checkout and reset have so many different modes of operation also make them confusing for beginners. The introduction of git switch and git restore should help with that, though.
What is your favorite Git-related tool/library, outside of Git itself?

Since I’ve heard of it I’ve been using diff-so-fancy as a way to make Git diffs more easily readable. Apart from that I mostly stick to the Git command line. Recently I discovered git-crecord, an ncurses interface for, among other features, interactive line-by-line staging.

Releases

Git 2.29.2
Git for Windows 2.29.2(2), 2.29.2(1)
GitHub Enterprise 2.22.4, 2.21.12, 2.20.21, 2.22.3, 2.21.11, 2.20.20, 2.19.26
Bitbucket Server 7.8
Gerrit Code Review 3.2.5.1, 3.2.5, 3.1.10, 3.0.15, 2.16.25, 2.15.21, 2.14.22
GitLab 13.6.1, 13.6, 13.5.4, 13.5.3, 13.5.2
GitKraken 7.4.0
GitHub Desktop 2.6.0, 2.5.7

Other News

Various

Announcing the Release of the Git Experience in Visual Studio; the new Git tooling is now the default source control experience in Visual Studio 2019, beginning with version 16.8.
Kernel.org manager Konstantin Ryabitsev announced that signed git pushes are now supported by the kernel.org system. Among other things, push signatures can be preserved in a commit transparency log, which is also now provided by kernel.org.

Light reading

Git before GitHub by Tarun Batra is a beginner-friendly article explaining how to submit patches using git’s built-in tools without using a platform like GitHub.
How to keep your Git history clean with interactive rebase by Tobias Günther on GitLab Blog. Interactive rebase is one of Git’s most versatile tools. Here’s how to use it to correct commit messages, fix mistakes, and more.
How I remember everything I learn by Aurelio Ogliari; he uses his personal wiki, which is nothing more than a Git repo (on GitHub), divided in folders with a bunch of READMEs in each of them.
GitHub Actions for semi-static web sites by Dave Cross on Dev.To explains how to keep a site up-to-date where there are only a few ways that it can change, like CPAN Dashboard. (GitHub Actions, then beta, were covered in Git Rev News #44).
What adding CI to 30 projects revealed by Gabor Szabo on Dev.To. Among others it found developer forgetting to add file to Git repository, or pushing some changes, or that build script depends on unreleased code or local configuration, or that not all dependencies were declared.
Nbdev: A literate programming environment that democratizes software engineering best practices by Hamel Husain on GitHub Blog. (See also nbdev’s mention in the ‘Git tools and sites’ section below.) nbdev builds on top of Jupyter notebooks to encompass the entire software development life cycle: automated generation of docs, Continuous Integration (CI), writing tests directly in notebooks, etc. Many of those features are integrated with GitHub (GitHub Actions, GitHub Pages, GitHub Codespaces).
Git is simply too hard: a fancified excerpt of Mislav Marohnić’s unpopular opinion on Go Time #153 podcast. See also Gitless, the experimental reworking of Git, based on research on difficulties in Git, mentioned in Git Rev News #20.
Gerrit Code Review fixes two important security vulnerabilities, Issue 13621 and Issue 13514. They have been found during the test migrations of the OpenDev Code Review service to the latest version v3.2. The issue was particularly sensitive for all those setups hosted in Europe, because of the potential exposure to other people’s personal information, such as e-mail and external ids, and was impacting only those very old setups that had recently migrated to v2.14 or later.

Git tools and sites

repositorch is a VCS repository analysis engine written in C#, which supports Git. It allows to get some basic and advanced statistics including LOCs, Burndown, Code ownership, Defect density and more.
Githru is an interactive visual analytics system that enables developers to effectively understand the context of development history through the interactive exploration of Git metadata. It uses novel techniques (graph reconstruction, clustering, and Context-Preserving Squash Merge (CSM) methods) to abstract a large-scale Git commit graph.
nbdev is a library that allows you to develop a Python library in Jupyter Notebooks, putting all your code, tests and documentation in one place. (See also nbdev’s mention in the ‘Light reading’ section above.) Among other features it provides a robust, two-way sync between notebooks and source code, and tools for merge/conflict resolution with notebooks in a human readable format. It is set-up out of the box for integration with GitHub Pages and GitHub Actions. Compare with nbdime – a tool for diffing and merging of Jupyter Notebooks, mentioned in Git Rev News #37, and jupytext – a plugin for Jupyter that can save Jupyter notebooks as Markdown documents, or Julia, Python or R scripts, or Review Notebook GitHub App (free for Open Source and Education).
Flagsmith (formerly Bullet Train) is an open source service to help release features with confidence by managing feature flags across web, mobile and server side applications. Hosted service is free for smaller projects.
Tara.AI is a product development service that helps provide clarity around the release cycle by connecting Git to tasks and sprints (with GitHub integration). Base tier free forever plan has unlimited tasks, sprints and workspaces, with no user limits; paid for features are planned.
Git Credential Manager Core (GCM Core) is a secure Git credential helper built on .NET Core that runs on Windows and macOS (Linux support is in an early preview). It replaces the .NET Framework-based Git Credential Manager for Windows (GCM), and the Java-based Git Credential Manager for Mac and Linux (Java GCM).
Git-completion is a friendly fork of the official Git completion and prompt scripts for Zsh and Bash. It’s a sister project of the Oh My Zsh gitfast plugin.
git-crecord is a git subcommand (written in Python), which allows users to interactively select changes to commit or stage using a ncurses-based text user interface.
ForgeFed - Federation Protocol for Forge Services. ForgeFed (formerly GitPub) is an upcoming decentralized federation protocol based on the W3C’s ActivityPub, which extends ActivityStream 2.0. It provides a server to server API for pull request, forking and subscription of repositories provided by Git web services (services like GitLab, Gogs, Gitea or SourceHut).
Visualizing Git Concepts with D3 is a website designed to help you understand some basic Git concepts visually, with sandboxes split by specific Git commands and a few specific real-world scenarios; adding/staging your files for commit is not covered.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Philippe Blain, Semyon Kirnosenko, Tarun Batra, Philip Oakley and Luca Milanesio.

Git Rev News Edition 68 (October 30th, 2020)

chriscool — Fri, 30 Oct 2020 11:06:51 +0000

Git Rev News: Edition 68 (October 30th, 2020)

Welcome to the 68th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of September 2020.

Discussions

Support

Apply Git bundle to source tree?

Andreas Grünbacher asked the mailing list if there was “a way to apply a particular head in a bundle to a source tree”. Using the Linux kernel as an example, he said he would like to create a bundle containing Git objects from version 5.8 to version 5.9-rc1:
```
$ git bundle create v5.9-rc1.bundle v5.8..v5.9-rc1
```
and then be able to “apply” this bundle either to an existing repository or only a source tree that would already contain code for version 5.8.

Taylor Blau replied to Andreas that there is no such thing as git bundle apply, but that git fetch and git pull can be used to update an existing repo from a bundle, for example:
```
$ git pull /path/to/bundle 'refs/tags/v5.9-rc1'
```
Andreas replied to Taylor that he was looking for a way to apply a bundle to an actual source tree, not a Git repository, but Taylor didn’t think it was possible.

Then another Andreas, Andreas Schwab, chimed in to discuss with Andreas Grünbacher what basis was needed to “apply” a bundle.

In the meantime Junio Hamano, the Git maintainer, replied to the original email from Andreas G. saying that a bundle created with “v5.8..v5.9-rc1” was not like a patch but rather “an equivalent of a (shallow) repository” that required having v5.8 for the bundle to be usable. Junio suggested ways to use such a bundle to update and then work in an existing repo that has v5.8, and asked for ideas to improve the git bundle documentation.

Andreas G. replied to Junio that the documentation was fine, and that he then saw that there’s simply not enough information in a bundle for what he wants to achieve on a source tree.

Konstantin Ryabitsev, a maintainer of kernel.org, also replied to Andreas G.’s initial email suggesting the following command:
```
curl --header 'Accept-Encoding: gzip' -L https://git.kernel.org/torvalds/p/v5.9-rc1/v5.8 |
  gunzip - | git apply
```
Andreas G. liked it, but said that the use case he was thinking about was to replace the patches that are, along with a baseline release, in source packages provided by Linux distributions. As bundles would provide actual Git history, they would be nicer than patches, if they could replace them.

Thomas Guyot-Sionnest replied that bundles could do that and that it was a “neat idea”. He said “bundles could be used for both the base release and patches”. The source packages would be “bigger initially than a single release”, but old bundles could help downloading just the additional bits needed for the next versions. That would help packagers as patches are “best maintained in Git” already.

Thomas also mentioned that he has been using bundles “since the very beginning” for backups as it’s “an efficient way to archive an entire bare repo into a single file and ship it offsite”.

Brian M. Carlson also replied to Andreas G. saying that “Debian considered using Git as part of the 3.0 (git) format”, but that there were issues with upstream having “non-free or undistributable material in their repositories”. “Tarballs can be repacked, but it’s harder to rewrite Git history to exclude objects.”

Developer Spotlight: Matheus Tavares Bernardino

Who are you and what do you do?

I’m a software developer and MSc student, living in São Paulo, Brazil. I started contributing to Git just over a year ago, through Google Summer of Code (GSoC). During the program, I was fascinated with the internal mechanics of Git and with Git features that I had not known until then. So, at the end of GSoC, I definitely wanted to stick around and learn more. Today, I’m working as a contract developer for Amazon, seeking to parallelize checkout and other Git operations.
What would you name your most important contribution to Git?

The improvements in git grep’s parallelism, during GSoC. With these changes, we’ve got up to 3.3x faster git grep searches in the object store, using threads.
What are you doing on the Git project these days, and why?

I’m currently working on parallelizing checkout. The parallel version has shown to be particularly effective for repositories located on SSDs or over network file systems (here are some benchmark numbers). The idea is to make it available to all commands that perform checkout: from the plumbing git read-tree to git clone, git sparse-checkout, and git checkout itself.

It’s been an exciting and challenging project! And containing patches and ideas from two previous parallel checkout approaches (by Duy and Jeff Hostetler), I think it really goes to show the power of collaboration and open-source.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Hmm, it would be nice to try to minimize the global states in the codebase. We have a fair amount of thread-unsafe operations, due to reads and writes to global variables or function-scoped static variables. Such variables do offer quite practical mechanics, but they can also hinder the process of adding multi-thread support. Furthermore, they are sometimes hard to locate, which can potentially lead to race conditions. The alternative approach, using multi-processes, usually requires writing more code for communication and synchronization (besides having an extra cost for subprocess spawning).
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Hmm, nothing comes to mind right now.
What is your favorite Git-related tool/library, outside of Git itself?

I rarely use Git-related tools besides Git itself. But I’ve always wanted to try and incorporate tig blame more in my daily life. I use git blame quite a lot, to dig through the code’s history and find answers regarding specific designs or implementations. In that sense, what I find most attractive about the tig interface, is that it allows to interactively load blame for parent commits, which is quite handy. I guess I still tend to go with the plain git blame out of habit.

Releases

Git 2.29.1, 2.29.0, 2.29.0-rc2, 2.29.0-rc1, 2.29.0-rc0
Git for Windows 2.29.1, 2.29.0
git-filter-repo 2.29.0
git-assembler 1.2
libgit2 1.1.0
GitLab 13.3.8, 13.5, 13.5.1, 13.4.4, 13.4.3, 13.4.2
Bitbucket Server 7.7
GitHub Enterprise 2.22.2, 2.21.10, 2.20.19, 2.19.25, 2.22.1, 2.21.9, 2.20.18, 2.19.24
GitHub Desktop 2.5.6
TortoiseGit 2.11.0

Other News

Various

The default branch for newly-created repositories (on GitHub) is now ‘main’.
The history of the term master in Git was covered in Git Rev News Edition #65, if one is interested.
Mercurial planning to transition away from SHA-1 [LWN.net]; discovering the problem with SHA-1 was discussed in Git Rev News Edition #25, and the state of SHA-1 transition in Git (in 2018) in Edition #41.
What’s cooking on Sourcehut? September 2020 and October 2020; Sourcehut, or sr.ht, is a software forge which was covered in Git Rev News Edition #46.
Google Summer of Code 2021 has been announced with significant changes compared to previous editions. Notably coding hours and period will be reduced from 350 hours and 12 weeks to 175 hours and 10 weeks; there would be 2 evaluations (instead of 3). Additionally, eligibility requirements will be relaxed, among others allowing people participating in a variety of different licensed academic programs, not just students of accredited university programs.
How Gitlab puts gRPC in the Real World talks about GitLab internals, especially access and management of Git repos through gRPC and a software layer written in Go called Gitaly.

Light reading

Sourcegraph: Devs are managing 100x more code now than they did in 2010 by Jim Salter on ArsTechnica.
Git scraping: track changes over time by scraping to a Git repository by Simon Willison on his weblog.
Pachyderm and the power of GitHub Actions: MLOps meets DevOps by Kathryn Hsu on GitHub Blog; Pachyderm, a data version control tool, was covered in Git Rev News Edition #49.
Project Cambria: Translate your data with lenses, about the Cambria tool to help translate between data schemas while maintaining compatibility between different versions, APIs and components.
Stockpiling blog posts for publishing when out of time with Git, a short article by Flavio Poletti.
The Code Review Guide by Camila Lenis on Dev.to.
Beginner’s guide to Git and Open-Source Contribution by William Otieno on Dev.to.
What is Git Rebase and How Is it Different from Merging? by Anthony Heddings.
How Git works inside: an interactive Docable notebook, rendered as static HTML with animated GIFs.

Git tools and sites

bit is an experimental modernized Git CLI, written in Go, built on top of git, that provides happy defaults and other niceties, with some commands taken from git-extras.
It takes some inspiration from Gitless, which was covered in Git Rev News Edition #20.
nb is a command line note-taking, bookmarking, archiving, and knowledge base application with plain-text data storage, encryption, and Git-backed versioning and syncing, written in Bash.
Cambria is a Javascript/Typescript library for converting JSON or YAML data between related schemas, via lenses (bidirectionally specifying a transformation). This helps version-control data exchange formats.
Codeberg is a collaboration platform and git hosting for free and open source software, content, projects. It is hosted in EU.
Git exercises is an open-source platform and service where one can learn and practice Git and discover its features, with the help of 23 exercises.
git-send-email.io by Sourcehut is a step-by-step tutorial on how to contribute to email-driven projects like the Linux kernel, PostgreSQL, or Git.

Credits

Git Rev News Edition 67 (September 24rd, 2020)

chriscool — Thu, 24 Sep 2020 11:06:51 +0000

Git Rev News: Edition 67 (September 24rd, 2020)

Welcome to the 67th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of August 2020.

Discussions

General

GSoC 2020 End

The Google Summer of Code 2020 officially ended on September 8, 2020. Congratulations to the three students who were mentored by the Git community, as they successfully passed all the evaluations! Their final reports and code submissions are available:
- Hariom Verma, who was mentored by Heba Waly and Christian Couder, worked on “Unify ref-filter formats with other --pretty formats”.
- Abhishek Kumar, who was mentored by Jakub Narębski and D. Stolee, worked on “Implement Generation Number v2”.
- Shourya Shukla, who was mentored by Kaartic Sivaraam and Christian Couder, worked on “Convert submodule to builtin”.

Reviews

[RFC PATCH 0/2]extend --abbrev support to diff-patch format

Đoàn Trần Công Danh sent a small RFC patch series that makes the diff machinery, which is used by git diff and similar commands, support the --abbrev option when it shows a patch.

In addition to the familiar --patch format, which is used when showing regular diffs in a way similar to the unified format of the Unix diff command, the diff machinery can produce the --raw format output to show object names before and after the change for each path like this:
```
:100644 100644 86e5411f39 f1b1bc8aa0 M  Makefile
```
In the --patch format, object names before and after the change appear on the index line, which looks like this:
```
index 4adb9ce124..67d9801da3 100644
```
The --abbrev option used to control the abbreviation of the object names in the --raw format but did not affect those shown on the index line in the --patch format. Đoàn’s patch series makes the option control both.

In the cover letter of his RFC patch series, Đoàn explained how the changes would improve his workflow when dealing with patches. But Junio Hamano and Jeff King, alias Peff, replied saying that they had trouble understanding the purpose of the series from the explanations in the cover letter.

After a discussion with Peff and Junio, it turns out that using the --full-index option is a better approach to help Đoàn’s workflow (the option was specifically designed to ensure that the index line in the --patch format can be used to exactly identify the objects involved in the change to help the users, which was what Đoàn’s workflow wanted). However, a consensus was reached that Đoàn’s patch series was worth moving forward, because it improved consistency between the diff formats.

So Đoàn sent a version 2 of his patch series with only changes in the cover letter and in the commit message of the second patch.

Junio replied to the first patch of the series though. This patch changed how --no-abbrev was dealt with. Junio asked for clarifications in the commit message, especially about why the patch was necessary.

So Đoàn sent a version 3 of his patch series with only changes in the commit message of the first patch. After further discussion with Junio, it appears that the patch was not actually necessary.

In the meantime though Gábor Szeder found that the tests in the second patch were failing when run with GIT_TEST_DEFAULT_HASH=sha256. This setting makes Git use the SHA-256 hash algorithm instead of the usual SHA-1 hash algorithm for object names.

A discussion about the best approach to fix this then followed between Đoàn, Junio and Brian M. Carlson, who has been working for a long time on implementing support for SHA-256 in Git.

Đoàn eventually sent a version 4 of his patch series, where the first patch of his version 3 had been discarded, but a new patch to improve handling of SHA-256 object names in the tests replaced it.

Junio and Đoàn discussed further improvements to the commit messages of both patches. Then Đoàn sent a version 5 taking these improvements into account.

The patch series has since been merged into the ‘master’ branch.

Developer Spotlight: Đoàn Trần Công Danh

Who are you and what do you do?

I’m just another average developer addicted to an exotic environment. Outside of my $dayjobs, I maintain Git and some other packages for VoidLinux.
What would you name your most important contribution to Git?

I would consider fixing remaining problems with musl libc my most important contributions to Git, since I mostly stay inside my musl box these days.
What are you doing on the Git project these days, and why?

I mostly watch for sideline these days, since I’m busy with other things. Occasionally, I jump in one or two discussion since that topic looks relevant to me. Sometimes, I write a patch or two to support my own jobs.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

I don’t have anything specific in mind, except the transition into the new hash algorithm, brian m. carlson has done a very good job, and I understand the transition would require a long transition period, testing, a lot of testing.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

The diff to merge-base notation (upstream…fork) of the diff family. This has been floating in the mailing list for a while, and I won’t waste this opportunity to not mention it again.

There’s an on-going change from Denton Liu to support --merge-base into the diff family. Hopefully, people can retrain their brain-muscles to use this new option instead.

Releases

GitHub Enterprise 2.22.0, 2.21.7, 2.20.16, 2.19.22, 2.21.6, 2.20.15, 2.19.21
GitLab 13.4, 13.3.6, 13.3.5, 13.3.4, 13.3.2, 13.3.1
Bitbucket Server 7.6
GitKraken 7.3.2, 7.3.1, 7.3.0
GitHub Desktop 2.5.5

Other News

Events

The first Git Contributors’ Inclusion Summit happened on Monday, September 14th, and Tuesday, September 15th. It was attended by around 30 people. Some notes were taken but it’s not clear if they are going to be publicly available.

Various

Set the default branch for newly-created GitHub repositories on GitHub Blog.
On October 1, 2020, if you haven’t changed the default branch for new repositories for your user, organization, or enterprise on GitHub, it will automatically change from master to main. You can opt out of this change at any time. Existing repositories will continue to have the same default branch they have now.
‘There is no way we can keep coding local’: GitPod’s cloud development platform released into sunlight of open source – The Register chats with co-founder Sven Efftinge.
Discussions have been going on about the Git project participating in the next Outreachy round. So far 3 projects have been proposed.

Light reading

Arista Networks, a Fortune 500 company, has rolled out mandatory commit signing across their Git repositories. Read about their journey at https://eos.arista.com/commit-signing-with-git-at-enterprise-scale/ and learn about how they:
- Manage code signing keys across a large company
- Enforce that all commits are signed
- Audit Git repositories to ensure that no unsigned commits are added.
Guillaume Papin in his development notes on a compilation database (a concept that includes, but is not limited to a JSON Compilation Database) includes section on Git as one of (and at this time the only) case studies on open source projects.

There is a patch by Philippe Blain to add support for generating a JSON compilation database to Git’s Makefile. It is currently merged into ‘next’.
Keith Peters writes how to create your own Git-based Wiki to save information that one might need later. The idea is to make use of the fact that many Git hosting sites render Markdown on-line, by storing the data in interlinked Markdown files – the article proposes the template to use.
Patterns for writing better git commit messages by Helder Burato Berto, with references to other articles, and a git commit template.
Learn Enough Git and Github to take part in the Weekly Challenge by Dave Cross (not intended as “beginners guide to Git and Github”).
Git Concepts and Workflow for Beginners by Juan Cruz Martinez on Live Code Stream.

Git tools and sites

ugit: DIY Git in Python is a tutorial to help learn about Git internals by building an implementation of Git in Python.
gitoxide (gix) is a command-line interface (CLI) to access Git repositories. It’s written to optimize the user-experience, and perform as good or better than the canonical implementation.

It provides an idiomatic, lean, fast and safe pure Rust implementation of Git, and it also provides an easy and safe to use API in the form of various small crates for implementing your own tools.
grokmirror-2.0 is a Git mirroring software announced by Konstantin Ryabitsev on the Git mailing list. It was developed by kernel.org for their own use.
GitQlient, pronounced as git+client (/gɪtˈklaɪənt/), is a multi-platform Git client written with Qt, originally forked from QGit.

Related project is GitQlientPlugin, the project to build an integrated QtCreator plugin of GitQlient.
Graphtage: A New Semantic Diffing Tool is a command line utility and underlying library for semantically comparing and merging tree-like structures such as JSON, JSON5, XML, HTML, YAML, and TOML files. You can even compare files that are in two different formats. When paired with the PolyFile tool you can semantically diff arbitrary file formats.
Sourcetrail is a free and open-source cross-platform interactive source explorer, that helps you get productive on unfamiliar source code. It currently supports C, C++, Java and Python.
git-in is a small Python script to import a message or an entire thread from a mailing list to an IMAP mailbox. Very useful when you are not subscribed to the list but want to answer an email from the list, while being be able to quote parts of the message.

Credits

Git Rev News Edition 66 (August 27th, 2020)

chriscool — Thu, 27 Aug 2020 11:06:51 +0000

Git Rev News: Edition 66 (August 27th, 2020)

Welcome to the 66th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of July 2020.

Discussions

Reviews

git-mv: improve error message for conflicted file

Chris Torek sent a patch to change the error message from git mv when it’s used on a file that has unresolved conflicts. Previously, in this special case git mv would error out with the same error message as if the file was not managed by Git, that is:

“fatal: not under version control, src=…”

This was of course misleading, so Chris’ patch implemented detecting this case and then using the new “must resolve merge conflict first” error message if applicable.

Eric Sunshine first reviewed the patch suggesting a small code improvement in the detection of this case, and a more succinct new error message, “conflicted”. Eric also commented on the test case that Chris’ patch added, suggesting a number of small changes that would make the test look more modern.

Junio Hamano, the Git maintainer, commented on the code detecting this case. He suggested a less wasteful way to do that.

Chris then replied to Eric’s review saying he will use Junio’s suggestion for the detection code and Eric’s suggestions for the error message and the test.

Chris also asked if he should clean up and modernize other tests in the test script that could benefit from Eric’s suggestions, but Eric replied that the test script, “t7001-mv.sh”, had so many old style issues that such improvements should happen in a dedicated patch series.

Interestingly Eric listed 17 different old style issues, and for each one he described what should be done to fix them, so that his email can be read as a guide to modernizing test scripts.

Elijah Newren replied to Junio’s suggestion, pointing to an email from two years ago, where the same issue was already discussed and where Junio suggested that git mv on a conflicting file could just move the file and remove its conflicting status, in the same way as git rm and git add already work on such a file.

Elijah said that he was still planning to implement what Junio had suggested in that email, but that in the meantime fixing the error message was perfectly fine.

Junio replied to Elijah saying that he was not convinced any more that what he had suggested two years ago was actually the right thing to do, and then describing in details some issues with his old suggestion. Junio agreed though that fixing the error message as in Chris’ patch was a “strict improvement”.

Elijah and Junio then discussed a bit more technical issues related to Junio’s old proposal.

Chris sent a version 2 of his patch implementing Junio’s and Eric’s suggestions, including the shortened “conflicted” error message that Eric had suggested.

Junio replied to Chris and discussed a bit the “conflicted” error message, but Chris’ version 2 patch got merged to the master branch as is.

Support

How can I search git log with certain keyword but without the other keyword?

孙世龙 sunshilong asked how to search for commits in git log that include certain keyword A, but at the same time do not have another keyword B in them. The example provided was a branch with three commits:

b90b03f b12
27f7577 b1
7268b40 t123

The original poster wanted to use git log --grep to find commits that match “12” but not “t123”. In this example it should return only “b90b03f b12” as search result.

Carlo Arenas proposed using features of PCRE syntax (Perl Compatible Regular Expressions) with a negative lookahead assertion and word boundary to generate expression that matches one but not the other:

git log -P --all-match --grep '12' --grep '\b(?!t123\b)\w+'

The syntax was explained by Jeff King, alias Peff, who also said that the short option -P had to be spelled --perl-regexp before Git version v2.14.0. He also reminded that for this to work one also needs a version of Git built with libpcre support.

It turned out however that it didn’t resolve the [more] real issue that sunshilong had:
I wonder why this command doesn’t work well.

I intend to find the comment with the keyword “12” but without “comments” whereas the output is something like this:
```
git log --perl-regexp --all-match --grep=12 --grep '\b(?!comments\b)\w+'
commit f5b6c3e33bd2559d6976b1d589071a5928992601
Author: sunshilong <sunshilong369@gmail.com>
Date:   2020-04-12 23:00:29 +0800

    comments 2020.04.12 ng
```
Peff responded that he can’t think of a way to achieve that just using a regex, and that currently Git supports similar feature only in git grep:
The natural thing to me would be the equivalent of:
```
  git grep -e 12 --and --not -e comments
```
The underlying grep machinery in Git understands how to compose multiple patterns like this, and the command above really does work (though of course it is searching for lines in a file and not commit messages).

But none of that is exposed via the command-line of “git log”. I think it would be possible to do so, but I’m not sure how tricky it would be (certainly one complication is that “--not” already means something else there, but presumably we could have “--grep-and”, “--grep-not”, etc).
The idea of introducing --grep-and and --grep-not to disambiguate from --not (which means something completely different for the log family) is as old as 2012, as Junio C Hamano reminded. He then went to explain the problem with properly implementing such feature:

Having said that, I do not think our underlying grep machinery is equipped to answer “find every commit whose log message has X but not Y”, even if we exposed the interface that is equivalent to that of “git grep” to “git log”.

There are two levels of boolean combination involved in running our “grep” machinery. The lower level is used to determine if each line matches the criteria. The main consumer of the “grep” machinery is of course “git grep” and because it is line oriented, we have quite a rich set of operations and combinations to say things like “if a line has X and Y on it in any order, but not Z on it, then the line is a match.” That is what “--not”, “--and”, “--or” (not exposed to the “git log” interface) express and we even take “(“ and “)” for grouping, e.g. “( X --or Y ) --and --not Z”.

Another level of combination is to determine if the entire document matches. It often happens that you want to find a document with both X and Y in it, and “grep -e X --and -e Y” is *NOT* a way to do so — the “--and” is a line-level combinator and tells the machinery to find lines that have both X and Y on them.

We have a fairly ad-hoc single mechanism for boolean combination at this level and that is the “--all-match” option, which says “Look at the boolean expression you used to find each matching line, and separate them at the OR operator at the top level. Now, apply the matching logic to all lines in a document and see if all the clauses joined by the top-level OR operators matched at least once. If yes, then the document matches.”

That is how “git grep --all-match -e X -e Y” finds documents that refer to both X and Y but not necessarily on the same line.

There is not much room for the line-level “--not” operator to participate in this picture. “git grep -e X --not -e Y” would mean “find lines that has X, or that does not have Y”, so as long as a document has one line with X on it and one line (which can be but does not have to be the same line) that does not have Y on it, the variant of that search with “--all-match” in it would say “yup the doc matches”. But that is definitely not what the user who wants to say “if a doc has X in it, I want to see it, but I do not want to see it if it also has Y” wants to see.

Then the discussion petered out, without much further help. It remains to be seen if somebody would take up the challenge of improving Git search capabilities by adding support for boolean combinations of line-level and document-level match operations.

Releases

Gerrit Code Review 3.2.3
GitHub Enterprise 2.21.5, 2.20.14, 2.19.20, 2.18.25, 2.21.4, 2.20.13, 2.19.19, 2.18.24
GitLab 13.3, 13.2.6, 13.2.5, 13.2.4, 13.2.3, 13.2.2
Bitbucket Server 7.5
GitKraken 7.2.0
GitHub Desktop 2.5.4

Other News

Various

GitLab is looking for a Backend Engineer with Git experience to join their Gitaly team. See the job description and apply through the GitLab Talent Community if you are interested.
China is building a GitHub alternative called Gitee (on TechCrunch).
Conditional steps and improvements to logs in Bitbucket Pipelines by Peter Plewa.

Light reading

Creating a GitHub Action to detect toxic comments using TensorFlow.js by Charlie Gerard (also on Dev.to), using TensorFlow’s toxicity pre-trained model.
What Is Git ? – Explore A Distributed Version Control Tool by Reshma Ahmed on the Edureka! blog.
Lecture 6: Version Control (git) (2020), part of lecture videos from the class offered during MIT’s Independent Activities Period in 2020, from the “Missing Semester” course providing hands-on introduction to tools and techniques in Computer Science.
Don’t ignore .gitignore by Rajeev Bera on opensource.com.
How to write a good commit message by Chrissie on Dev.to; one of many such articles.
Searching code with Sourcegraph [LWN.net] by Ben Hoyt. Open-sourcing Sourcegraph was covered in Git Rev News #44 (October 24th, 2018).
Using Git with WordPress — Part 1 by Kristian Lumme.
A Resource for all Things Git by Lea Cohen on codeburst.io is a list of articles about Git, with descriptions.

Git tools and sites

Sourcegraph Cloud allows to search “top” public repositories from various code hosting sites, while self-hosted instances can be used to also search private and local repositories; there are also browser extensions for Chrome and Firefox that enable its features to be used when browsing on hosts like GitHub and GitLab.
Autohook is a very, very small Git hook manager in bash with focus on automation.
RepoZ is a zero-conf git repository hub for Windows and macOS, providing a navigation widget allowing for quick overview of your repositories, with a sidekick command line app called grr and Windows Explorer enhancements.

Credits

Git Rev News Edition 65 (July 29th, 2020)

chriscool — Wed, 29 Jul 2020 11:06:51 +0000

Git Rev News: Edition 65 (July 29th, 2020)

Welcome to the 65th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of June 2020.

Discussions

General

The history of master in Git (written by Andrew Ardill)

Amidst all the discussion around changing the default branch from master to something else, many people have asked why master was chosen in the first place. As master has a few different meanings in English, just which meaning was intended?

Konstantin Ryabitsev was the first to discuss the meaning of master, saying

Git doesn’t use “master-slave” terminology – the “master” comes from the concept of having a “master” from which copies (branches) are made

This post from the GNOME mailing list was then linked by Simon Pieters with the claim that

Git’s master is in fact a reference to master/slave

That post points out that the first use of master was in a CVS helper script, links that to BitKeeper (the version control system used to manage Linux development when Linus Torvalds first wrote Git), and claims BitKeeper used the “master and slave” meaning of master.

Many people considered master to mean a “master copy”, so this connection to slavery was very surprising.

Andrew Ardill investigated the BitKeeper source code and came to the conclusion that “the overwhelming majority of [the usages of master in BitKeeper] are of the “Master Copy” variant”, or as Michal Suchánek said “even in BitKeeper the use of master/slave is the exception rather than the norm.”

Off the list discussions were ongoing, and Petr Baudis wrote on Twitter about naming the master branch in Git

I picked the names “master” (and “origin”) in the early Git tooling back in 2005.

(this probably means you shouldn’t give much weight to my name preferences :) )

I have wished many times I would have named them “main” (and “upstream”) instead.

Glad it’s happening @natfriedman

When asked for which meaning of master was intended, Petr replied

“master” as in e.g. “master recording”. Perhaps you could say the original, but viewed from the production process perspective.

A clueless Central European youngster whose command of English was mostly illusory came up with the term, which is why it isn’t very obvious…

In a follow-up to that original GNOME mailing list post, Bastien Nocera retracted their claims from the original post, saying

I emailed Linus Torvalds recently… and he told me that it was unlikely that the “Git master” branch name was influenced by BitKeeper, and that “master” was “fairly standard naming” for this sort of thing and “more likely to be influenced by the CVS master repository”

Going on, Bastien discusses Petr Baudis’ tweets and then concludes “it doesn’t matter where the name comes from… The fact that it has bad connotations, or inspires dread for individuals and whole communities, is reason enough to change it.”

This is something that Brian M. Carlson had also pointed out on the Git mailing list, saying

“master”, even though from a different origin, brings the idea of human bondage and suffering to mind for a non-trivial number of people, which of course was not the intention and is undesirable. I suspect if we were making the decision today, we’d pick another name, since that’s not what we want people to think of when they use Git.

Brian goes on to lay out changes required in Git to rename master as the default, suggesting that there is a decent amount of work and that due to compatibility concerns “we’d probably want to make it in a [Git version] 3.0”.

Around the web the discussion about renaming master continues. The incorrect claims around the history of master persist, even in our own Git Rev News: Edition 64, but seem to be quickly corrected where possible such as on GitLab’s discussion on the topic.

Reviews

More commit-graph/Bloom filter improvements

Derrick Stolee, who prefers to be called Stolee, sent a patch series to the mailing list, based on a previous experimental patch series sent a few weeks earlier by Gábor Szeder.

When he sent his patch series, Gábor said that his work was a proof of concept started more than a year ago, that he had no time to finish yet. He was motivated to send it as-is with changes to commit messages, when he recently took a look at the current changed-path Bloom filter implementation. This implementation was developed for a long time mainly by Garima Singh and was merged at the beginning of May. He saw that it had some of the same issues that he had stumbled upon, and that it missed some optimization opportunities.

Gábor listed a lot of very interesting benefits from his work, but also a lot of drawbacks that would prevent it from being merged as is. Many of the benefits are linked to a new format used to store the changed-path Bloom filter. This new format was justified by an impressive commit message.

Stolee, Taylor Blau, Johannes Schindelin and Junio Hamano, when reviewing Gábor’s work, were disappointed that Gábor was not trying to contribute to the current implementation. It appeared though that a number of Gábor’s 34 patches and ideas could be applied on top of the current implementation.

That’s what Stolee did by first sending 10 patches from Gábor’s series at the beginning of June. This patches series required a bit of work, but Stolee left out what would have been more difficult to apply to the current code. René Scharfe, Stolee, Gábor and Junio commented a bit on it, but didn’t find anything that would require a new version of this patch series. So it is now “cooking” in the ‘next’ branch.

Stolee’s next patch series called “More commit-graph/Bloom filter improvements” was about adding a few extra improvements, several of which are rooted in Gábor’s original series. Even though Gábor’s patches did not apply or cherry-pick at all, Stolee still credited Gábor as the author of 4 patches out of 8.

Anyway this new series contained 2 changes that improve the false-positive rate which increases performance, and one change that improves usability. René and Taylor suggested improvements and bug fixes. Taylor even sent a patch.

Stolee then sent a version 2 of the series, taking into account the feedback and adding the patch from Taylor to the series. René, Gábor, Junio and Stolee discussed a few more points.

That led to Stolee sending a version 3 in which Gábor reported a bug that Stolee subsequently fixed.

So Stolee sent a version 4 which is now cooking in the ‘next’ branch, along with the first series that has 10 patches from Gábor.

In the meantime though Gábor commented on this first series saying that it has a number of issues. Hopefully these issues will be addressed soon, and these 2 patch series will be merged in the near future.

Developer Spotlight: Jonathan Tan

Who are you and what do you do?

I’m a Software Engineer at Google who works on Git. I also contribute to JGit (a Java implementation of Git) as one of its committers.
What would you name your most important contribution to Git?

I would say “partial clone” - the ability to clone a repository, but not necessarily have all of that repository’s objects (accumulated throughout its history) in your clone. Quite a few articles have been written about it, but in summary, it improves Git performance especially for large repositories.
What are you doing on the Git project these days, and why?

The thing that immediately comes to mind is “partial clone”. The fundamentals are there, but some Git commands still operate under the assumption that objects are only a disk read away (instead of a network fetch - in a partial clone, if an object is needed but missing, it is automatically fetched). I’m improving those commands to be more cognizant of this fact - typically, this means batching the fetch of all the objects it will need once it realizes that it does not have some of them, instead of “I need this object, so go fetch it; OK let me process it; oops I need another one, so go fetch that”.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Along the lines of “partial clone” and large repositories, I would like them to investigate the feasibility of having Git servers be able to serve results of computations (thus, not just objects). One case is git blame - if a Git client could ask a Git server to send the results of such a command, it could offload most of the computation to the server, only needing to build upon the server’s results with the locally-created objects that the server does not know about. This is especially useful with partial clone, because the client does not even have most of the objects needed and would have to fetch them otherwise.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

One small thing that I can think of: remove the ability of git reset to update the working tree and the objects staged in the index. The git restore command, relatively recently introduced, does this with more beginner-friendly parameter names (--worktree and --staged, respectively, instead of the --hard, --mixed, and --soft of git reset). This change would make it easier, for example, to read scripts written by other people - I would no longer need to think so much about what that reset in the script would do.

Releases

Git 2.28.0, 2.28.0-rc2, 2.28.0-rc1, 2.28.0-rc0
Git for Windows 2.28.0, 2.28.0-rc2, 2.28.0-rc1, 2.28.0-rc0
git-filter-repo 2.28.0
Bitbucket Server 7.4
Gerrit Code Review 3.1.8, 3.0.12, 2.16.22
GitHub Enterprise 2.21.3, 2.20.12, 2.19.18, 2.18.23, 2.21.2, 2.20.11, 2.19.17, 2.18.22
GitLab 13.1.5, 13.2.1, 13.2, 13.0.10, 13.1.4, 13.1.3, 13.0.9 and 12.10.14, 13.1.2, 13.0.8 and 12.10.13
GitKraken 7.1.0
GitHub Desktop 2.5.3

Other News

Events

Carmen Andoh, who works for Google, and Jonathan Nieder’s team at Google have volunteered to organize a Git Inclusion Summit. It would be a virtual contributor summit with the purpose of engaging core Git contributors as active participants in diversity and inclusion initiatives for the Git project. Interested Git contributors can vote on their preferred summit duration and times on a whenisgood poll by Thursday, July 30th.

Various

Junio Hamano, the Git maintainer, has renamed the pu branch of git.git to seen. This has been done to use a more meaningful name and make room for topics from those contributors whose two-letter name abbreviation needs to be ‘pu’. This was announced in “What’s cooking in git.git (Jun 2020, #04; Mon, 22)”
The Git Project Leadership Committee has been briefly interviewed via email by Elizabeth Landau for an article in Wired about current changes to Git’s default name for the initial branch.
Highlights from Git 2.28 by Taylor Blau on GitHub Blog, mentioning among others init.defaultBranch, changed-path Bloom filters, the git bugreport command and git log’s new --show-pulls option.
The Tower Git client for Windows and MacOS now supports CMD+Z for Git (a universal undo).
Exciting new updates to the Git experience in Microsoft Visual Studio 2019.
GitHub Archive Program: the journey of the world’s open source code to the Arctic by Julia Metcalf on GitHub Blog. The GitHub Archive Program along with the GitHub Arctic Code Vault were introduced at GitHub Universe 2019, and mentioned in Git Rev News #57 (November 20th, 2019).
Updating the Git protocol for SHA-256 [LWN.net] by John Coggeshall.

Light reading

Git Rebase - A Complete Guide by Brooke Kuhlmann at Alchemists.
How to safely use GitHub Actions in organizations by Nicholas C. Zakas, mainly about handling credentials and other secrets. Various tools for checking the repository for secrets and/or safely storing secrets were mentioned in Git Rev News Edition #25, #28, #36, #39 and #57
Fedora Classroom: Git 101 with Pagure session was streamed on YouTube on the Fedora Project channel.
How To Create A GitHub Profile README by Monica Powell on Dev.to.
Top 13 GitHub Alternatives in 2020 [Free and Paid] by Momchil Koychev on DevOps Zone.
Git Best Practices – AFTER Technique by Rajeev Bera on DevOps Zone.
6 best practices for teams using Git by Ravi Chandran on OpenSource.com.
Use broot and meld to diff before commit by Denys Séguret (author of broot, which is a tool to navigate file trees).
Basic Git Analogy for Contributing to Open Source Project by Sagar Seghal on Medium.
Can You Restore A Deleted Commit on Git? by Dmytro Khmelenko on Hacker Noon (the answer is yes, with the help of the reflog).
Git Concepts I Wish I Knew Years Ago by Gabriel Abud on Dev.to.

Git tools and sites

Git Lint - A command line interface for analyzing Git commit quality and consistency for yourself and/or team. Can be used as a Git Hook and/or wired into your continuous integration build system.
git-assembler: update git branches using high-level instructions; it can perform automatic merge and rebase operations following a simple declarative script (like “make”, for branches).
git-manpages-l10n is repository for translating Git manpages (the Git documentation).
icdiff is improved colored diff. Instead of trying to be a diff replacement for all circumstances, the goal of icdiff is to be a tool you can reach for to get a better picture of what changed when it’s not immediately obvious from diff. Docs include examples on how to integrate it with Git, Mercurial and Subversion.
Guitar is a multi-platform graphical Git client under development, written in C++ and powered by Qt.
SCM Breeze is a set of shell scripts (for bash and zsh) that make it easier to use Git. It integrates with your shell to give you numbered file shortcuts, a repository index with tab completion, and a community driven collection of useful SCM functions. SCM Breeze lives on GitHub at https://github.com/ndbroadbent/scm_breeze
Gitpod - Prebuilt Dev Environments for GitLab, GitHub and Bitbucket; on the cloud or self-hosted, with a free tier.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Andrew Ardill, Jonathan Tan, Brooke Kuhlmann, Eric Sunshine, Carlo Marcelo Arenas Belón and Gábor Szeder.

Git Rev News Edition 64 (June 25th, 2020)

chriscool — Thu, 25 Jun 2020 11:06:51 +0000

Git Rev News: Edition 64 (June 25th, 2020)

Welcome to the 64th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of May 2020.

Discussions

Reviews

fetch: allow adding a filter after initial clone

Xin Li sent a patch to allow using a partial clone filter when fetching even if the original clone didn’t use one.

As the patch was lacking a proper commit message, Junio Hamano, the Git maintainer, asked Xin to add one. So Xin sent an explanation of what the commit does taking as an example a shallow clone, with git clone --depth=1 ..., that is transformed into a partial clone with git fetch --unshallow --filter=blob:none .... Xin wrote that being able to do so is easier for the user than having to manually set the core.repositoryFormatVersion and extensions.partialClone config options.

Junio replied asking how we could be sure that the server actually supports the protocol extensions required for partial clone, as setting up the config options manually or automatically shouldn’t be done without verifying that.

Brian Carlson also replied to Xin’s initial patch wondering if it was safe to set the core.repositoryFormatVersion to 1 as it would make Git fail if any already configured extensions.* config option, like extensions.tomatoSalad, was not recognized.

Xin then sent a version 2 of his patch. This time there was a commit message in the patch and a cover letter along with the patch that explained the changes. The patch itself added tests and checked that the existing configuration had no unsupported extensions.* configuration before upgrading the core.repositoryFormatVersion config option to 1.

Jonathan Nieder reviewed the patch suggesting a number of small changes and moving some content from the cover letter to the commit message. Xin then sent a version 3 of his patch applying Jonathan’s suggestions and without a cover letter.

Junio in the meantime commented on the version 2 that it was not enough to check that the existing configuration had no unsupported extensions.* configuration variable, but that instead the code should check that there is no extensions.* configuration variable at all, as any such configuration variable could have an unsupported value. Jonathan then agreed with Junio.

Xin replied to them that the current code doesn’t actually check repositoryFormatVersion, so setting extensions.partialclone is enough to make git fetch --filter=... work. He then asked what we want to do about this situation.

Jonathan replied that this should be fixed even though it was a separate concern from the patch.

Xin then sent a version 4 of his patch taking into account Junio’s comments. Junio reviewed it and suggested other improvements. He further elaborated on core.repositoryFormatVersion upgrade by suggesting the following criteria:

(1) if upgrading from v0, there must be no extensions.* and

(2) if upgrading from other versions, there must be no extensions.* we do not recognize.

Jonathan also reviewed version 4 of Xin’s patch focusing on the changes made in tests.

Xin sent a version 5 of the patch addressing the comments. He also replied to Jonathan’s review. Junio also replied to Jonathan’s review agreeing with him that some changes in the patch actually belong to another patch.

Xin then sent a version 6 with 4 patches instead of 1. Junio reviewed the patches and found that only the last one could be controversial as it could perhaps break an existing set-up.

The last patch indeed contained the changes about checking repositoryFormatVersion that Jonathan and Junio wanted to see separately. With that patch the extensions.* config options don’t take effect unless core.repositoryFormatVersion has been upgraded to 1 or higher.

So for example if extensions.worktreeConfig is set to true but core.repositoryFormatVersion isn’t set, then with the patch Git will behave as if extensions.worktreeConfig wasn’t set.

Junio thinks that this change is the right thing to do in the longer term though. He asked for comments about that but no-one answered. So the patch series has been merged to ‘pu’ and then ‘next’ and according to the last “What’s cooking in git.git” email from Junio, the plan is to merge to ‘master’.

Releases

Git 2.27.0
Git for Windows 2.27.0(1)
git-filter-repo 2.27.1, 2.27.0
libgit2 1.0.1
GitLab 13.0.6, 12.10.11, 12.9.10, 12.10.10, 13.0.5, 13.0.4, 12.10.9, 12.9.9, 12.10.8, 13.0.3, 13.0.1, 12.10.7, 12.9.8
Bitbucket Server 7.3
Gerrit Code Review 3.2.2, 3.1.7, 3.0.11, 3.2.1, 3.1.6, 3.0.10, 2.16.21, 2.15.19, 2.14.21, 3.2.0, 2.16.20, 3.1.5, 3.0.9
GitHub Enterprise 2.21.0, 2.20.9, 2.19.15, 2.18.20
GitKraken 7.0.1
GitHub Desktop 2.5.2, 2.5.1

Other News

Various

The Git PLC (Project Leadership Committee) announced that it drafted a statement “regarding Git and branch naming” with the Software Freedom Conservancy that has been posted at Conservancy’s site. Articles related to this issue include:
- Proposal to Rename the ‘Master’ Branch of WordPress-Owned Git Repositories
- Loaded terms in free software [LWN.net]
- Replacing master in git
- Migrating your default git branch to ‘main’
- GitHub to replace “master” with alternative term to avoid slavery references; note that while BitKeeper used master/slave terminology for repositories, ‘master’ branch in Git is about being ‘master copy’
Eric Wong, the developer of public-inbox.org, implemented a read-only IMAP/IMAPS server, so that a Git mailing list archive can now be accessed through initially 8, and now 9, IMAP mailboxes sliced into ~50k messages to not overload clients.
Matheus Tavares, who was a GSoC student last year, has been hired as a freelancer by Amazon to improve Git performance. Congratulations to him!
A new Hacking Git page lists documents helpful to develop Git.
Introducing GitHub Super Linter: one linter to rule them all by Lucas Gravley on GitHub Blog.
DVC 1.0 release: new features for MLOps; the 1.0 Pre-release was mentioned in a previous edition of Git Rev News.

Light reading

Using GitHub Actions for MLOps (Machine Learning Operations) & Data Science by Hamel Husain on GitHub Blog.
How to squash git commits by Srebalaji Thirumalai.
Rebase and retag and Rebase and retag, but manually is a series of short articles by Flavio Poletti on how to use tagging to schedule blog article publication and how to use rebase to change planned publishing date.
Reordering git commits (not patches) with interactive rebase by Mark Dominus (a very specific use-case).
Speeding up a Git monorepo at Dropbox with <200 lines of code by Utsav Shah on Dropbox.Tech .
Using make and git diff for a simple and powerful test harness by Chris Morgan
Git Explained: Proper Team Etiquette by Milu.

Git tools and sites

Piranha by Uber is an Open Source tool for automated clean up of stale code caused by feature flags that are no longer required. It currently supports Java, Swift, and Objective-C.
git-fuzzy is a CLI interface to Git that relies heavily on the fzf general-purpose command-line fuzzy finder (version 0.21.0 or higher).

Credits

Git Rev News Edition 63 (May 28th, 2020)

chriscool — Thu, 28 May 2020 11:06:51 +0000

Git Rev News: Edition 63 (May 28th, 2020)

Welcome to the 63rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of April 2020.

Discussions

General

GSoC 2020 Students and Projects

The following three students have been officially accepted to work on Git as part of the GSoC (Google Summer of Code) 2020:
- Abhishek Kumar will work on Implement Generation Number v2. He will be co-mentored by Jakub Narebski and Derrick Stolee. More information is available on his proposal and blog.
- Hariom Verma will work on Unify ref-filter formats with other --pretty formats. He will be co-mentored by Heba Waly and Christian Couder. More information is available on his proposal and blog.
- Shourya Shukla will work on Convert submodule to builtin. He will be co-mentored by Kaartic Sivaraam and Christian Couder. More information is available on his proposal and blog.
It will be the 13th Summer that the Git project will mentor students as part of the GSoC. Shourya, Hariom and Abhishek will be the 30th, 31st and 32nd students mentored since 2007 when Git started participating in the GSoC.

It will be the 16th year of the GSoC, but unfortunately because of the current sanitary situation in the world, there will be no GSoC Mentor Summit, and no swag will be sent to participants this year.

Reviews

remote.c: fix handling of push:remote_ref

Last February Damien Robert sent a patch to change how ‘ref-filter.c’ interprets %(push:remoteref).

Damien had already sent a patch in April 2019 to fix another bug in ‘ref-filter.c’ related to %(push:track). This patch was incorporated in Git 2.22.

‘ref-filter.c’ is some internal API that formats information about Git refs or Git objects. It’s used by commands like git branch and git for-each-ref.

The issue Damien wanted to fix was that ‘ref-filter.c’ didn’t take into account the push.default config option which is used when no refspec is specified for the push.

Peff, alias Jeff King, replied to Damien, and made it clear that it was about taking push.default into account. He also found that Damien’s patch wouldn’t work in the case where push.default was set to upstream and a branch has been set to track a specific branch different than the default one.

Peff then commented on the code and asked for some tests, saying that the current tests were not covering this case and that they would wrongly fail if Damien’s patch was applied.

Damien replied to Peff agreeing about the upstream case and to add more tests. He found that his initial code also wouldn’t work when push.default was set to nothing.

Peff and Damien discussed a bit more some details of the possible changes in the code, while Peff proposed a preparatory patch to clean up the current code before Damien’s changes. Then Damien sent a version 2 of his patch along with Peff’s preparatory patch.

The version 2 handled all push.default cases and added tests for them, but Junio Hamano, the Git maintainer, suggested improvements in the commit message of the preparatory patch. Peff suggested improvements of his own but agreed with Junio’s suggestion too.

Meanwhile Damien found issues in version 2 of his own patch, and separately Junio commented on it and suggested some improvements. Damien and Junio soon agreed, and then Damien sent a version 3 of his patch. This version contained only Damien’s patch, as Peff’s patch was merged separately.

Peff found a memory leak around Damien’s patch, but the leak had already been there before the patch. Peff also suggested small improvements to the tests, and eventually sent his own version of Damien’s patch for him to “to try it out or hack on it further”.

Damien found an issue in Peff’s patch though, and, after improving the tests in his patch, more existing issues in the current code in case of a triangular workflow. Peff commented that these issues could be left for a separate fix though.

Damien then sent a version 6 of his patch, though the title in the cover letter mistakenly contains “v4”, saying version 4 and version 5 were intermediate versions he made but did not send to the mailing list.

This version contained a preparatory patch to fix the triangular workflow issues Damien had found, as well as his updated patch with tests for both his fixes in this patch and the triangular workflow fixes. However, this patch series was marked as RFC, since its first patch was not very polished and did not fix all corner triangular workflow cases.

This led to some release confusion as Junio then had merged the 2 patches to the next branch, while Damien had sent a version 8 that contained only his patch without the triangular workflow fixes and test cases.

This last version is now merged in the pu branch, and is likely to find its way to master, while hopefully the fixes related to triangular workflows will be re-sent separately.

Releases

Git 2.27.0-rc2, 2.27.0-rc1, 2.27.0-rc0
Git for Windows 2.27.0-rc2, 2.27.0-rc1, 2.27.0-rc0
GitHub Enterprise 2.20.8, 2.19.14, 2.18.19, 2.17.25, 2.20.7, 2.19.13, 2.18.18, 2.17.24
GitLab 13.0, 12.10.6, 12.10.5, 12.10.3, 12.10.2, 12.9.5, 12.8.10
Bitbucket Server 7.2
Gerrit Code Review 2.16.19, 2.16.18
GitKraken 7.0.0
GitHub Desktop 2.5.0, 2.4.3
isomorphic-git 1.0.0

Other News

Various

New git-filter-repo resources: a cheat sheet for converting filter-branch commands which shows equivalents for all examples from the filter-branch manpage, and a similar cheat sheet for converting BFG repo cleaner commands which shows equivalents for all the examples from the BFG web page.
Java 16: Migration to Git and GitHub gets closer (from Mercurial).
Why AppsFlyer moved from Bitbucket to [self-hosted] GitLab.
GitHub Codespaces lets you code in your browser without any setup; see also New from Satellite 2020: Start coding in seconds on GitHub with Codespaces.
DVC 3 Years 🎉 and 1.0 Pre-release 🚀; DVC (Data Version Control), an open-source version control system for Data Science projects was first mentioned in Git Rev News #42.

Light reading

Patterns for Managing Source Code Branches by Martin Fowler (author of the Refactoring: Improving the Design of Existing Code book); note that this article is being released in installments, and at the time of publishing this edition it finished describing all the patterns but was not yet complete.
How LinkedIn handles merging code in high-velocity repositories by Niket Parikh.
How to Set up the HTTP Git Server for Private Projects on Ubuntu 18.04 with nginx, by Jack Wallen.
Git on Windows by Gabor Szabo, a video series where you can learn how to use Git on MS Windows (half of links to videos are behind a Code Maven paywall).
Git Explained: The Basics by Milu Franz.
Git Explained: An In-Depth Comparison of the commands revert, checkout, reset, merge, and rebase by Milu Franz.
The life-changing magic of git rebase -i by Dave Neary.
How to resolve a git merge conflict by Brian Breniser.
Managing Git projects with submodules and subtrees by Manaswini Das.
Improve Git Diffs for Structured Data by fREW Schmidt. The solution uses .gitattributes and a custom shell script for wrapping the git diff command, using jq and sponge to process JSON files.
Comparing Code Quality Meta Tools, that is linters and beautifiers operating on the whole project (many of those tools being systems for managing Git hooks): tidyall, pre-commit, lefthook, husky, overcommit, and precious; article by Dave Rolsky.

Git tools and sites

Fork, a fast and friendly proprietary git client for Mac and Windows (with free evaluation).
Git-Stats is an open-source GitHub contribution analyzer service written in Node.js.
Git Insights is an open-source analytics tool to give you insights on your software projects and teams, currently supporting only GitHub (as GitHub App); support for Bitbucket, GitLab and self-hosted repositories is planned.
GitSavvy is an open-source Sublime Text 3 plugin providing full Git and GitHub integration.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Johannes Schindelin, Elijah Newren and Damien Robert.

Git Rev News Edition 62 (April 23rd, 2020)

chriscool — Thu, 23 Apr 2020 11:06:51 +0000

Git Rev News: Edition 62 (April 23rd, 2020)

Welcome to the 62nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of March 2020.

Discussions

General

Happy birthday to all of us ;-)

On April 7, Junio Hamano, the Git maintainer, sent a happy birthday message to the mailing list to celebrate that “it was today 15 years ago that Linus announced the availability of the first tarball of Git”.

Junio thanked the contributors and everyone in the ecosystem, including people from the Software Freedom Conservancy and employers of contributors.

His email ended with “Thanks all, and let’s look forward to see the next 15 years be as wonderful years for Git as the past 15 years ;-)”

A number of people replied especially thanking Junio for his work as the maintainer of the project. Edward Thomson, who is a maintainer of libgit2, also thanked everyone, on behalf of libgit2.

Let’s all also thank Junio, Linus and every contributor in the Git ecosystem!

Support

Regression in v2.26.0-rc0 and Magit

Jean-Noël Avila reported to the mailing list that git version 2.26.0-rc0 segfaulted under Magit with auto-revert enabled.

Magit is a popular Emacs interface to Git, and the auto-revert mode lets Emacs revert files that have changed on disk when a Git command has been run outside of Emacs.

Jean-Noël had bisected the issue to a commit that was improving the error message which Git issues when it dies due to processing a path outside the repository. This commit though didn’t consider the case of a bare repo which triggered the segfault.

Jonathan Nieder replied that the bug was fixed by another commit by Emily Shaffer that had not yet made it to the master branch. He asked Junio Hamano, the Git maintainer, if the commit could be fast-tracked, and Emily if she could add a test to her commit.

Junio replied suggesting that a few tests should be added, and that there were a few days left before v2.26.0-rc2 to add them. The next day though Junio replied to himself with a patch adding the tests and asking for comments.

Jonathan Nieder reviewed Junio’s tests adding his “Reviewed-by:”, and said that Emily was out of office so they were well timed.

Junio replied to himself again discussing one test he wrote that tested that both git log -- .. and git ls-files -- .. fail when the current working directory is the .git directory.

He wondered why, if “.” instead of “..” is used in the above commands, Git should behave as if the current working directory was the top-level of the working tree instead of .git, and why Magit is expecting cd .git && git ls-files .. to show the entire working tree.

Kyle Meyer replied to Junio that internally Magit’s call which triggered the bug is running git ls-files from .git to ask whether the file used to edit a commit message is actually tracked, as it makes no distinction between files in .git and in the working tree. He said that he would propose a change in Magit to improve this.

Gábor Szeder also replied to Junio’s patch suggesting a small improvement in the tests which Junio accepted sending an improved patch.

The fix with Emily’s code and Junio’s tests was then merged into v2.26.0-rc2.

Developer Spotlight: Eric S. Raymond

Who are you and what do you do?

I’ve been an open-source hacker since long before that term was coined. Back around the turn of the century I wrote “The Cathedral and the Bazaar”, which helped reinvent the movement and gained it mainstream acceptance. I’m also the author of “The Art of Unix Programming”. More recently I’ve headed the GPSD and NTPsec projects. My most Git-relevant work is reposugeon.
You’ve recently gifted us with an article about reposurgeon on Git Rev News edition 60, is there something you would like to add about reposurgeon, its history, or the article?

Probably the most interesting additional thing I can say is that I discovered a fundamental strategy for designing good DSLs (Domain-Specific Languages) while working on reposurgeon.

Here it is: Whatever domain you’re trying to capture, first develop a way to do that capture in a declarative markup. Then write an editor for that markup, and you will implicitly have a DSL that spans the domain. It’s rather like the mathematical concept of a functor.

In reposurgeon’s case, the domain is Git repositories and the declarative markup is fast-import streams. Reposurgeon is all about exploiting that equivalence.
You used reposurgeon to migrate the GCC repository, which has about 280K commits, from SVN to Git. Can you tell us a bit more about the context in which such migrations happen. Like what are the timelines, goals, tools, people, etc involved in such migrations?

I’ve already written about this in some detail here. I’m going to be reworking that over the next couple of weeks based in part on the GCC experience and in part to reflect the unfortunate fact that Mercurial isn’t really a contender any more.

One thing that has been on my mind recently is the importance of having a “Mr. Inside”. The ideal team to do a major conversion pairs a reposurgeon expert (Mr. Outside) with a project member who knows the history of the repository intimately, can make policy decisions, and is willing to learn enough about reposurgeon to edit the recipe.

On GCC we had the ideal situation - the project lead chose to be Mr. Inside. And a good thing, too - this conversion was difficult.
Can you describe how Git is related to reposurgeon, other software you have been working on and your work in general?

Reposurgeon depends on the leverage offered by git fast-import streams. It uses them as an interchange format between different version-control streams. Conversely, Reposurgeon (and a front-end I also maintain, cvs-fast-export) enables higher-quality migrations from older VCSes than anyone has ever been able to do before.

As for how it relates to my other work, there is cvs-fast-export. I didn’t write the crucial analysis parts of cvs-fast-export myself; Keith Packard of X fame did that, it used to be called cvsparse. I did rescue it and give it the ability to emit a fast-import stream, because reposurgeon needed a better CVS importer than I could find elsewhere.

More generally, I love writing DSLs and will take pretty much any opportunity to do that. I have especially enjoyed inventing and working on reposurgeon because - well, I used to be a mathematician. I like working on things where graph theory and abstract algebra are important. Reposurgeon scratches that itch.
What is something about Git or its ecosystem that you admire?

How freaking comprehensive it is. Pretty much anything you can imagine wanting to do with a version-control history there is tool support for somewhere.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

That’s easy. I’d port it to Go and toss out the C code. C still has its uses, but for anything without hard latency requirements C is now obsolete. Not something I would have said even three years ago, but times change.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

There’s a weird feature I’ve forgotten the name of where you can pass around binary pack files rather than MRs or patches. Ah, git bundles, that’s it. Having worked with it once, I hate the lack of transparency, that you can’t easily eyeball a bundle before you apply it. I’d shoot that feature through the head in a heartbeat.

If I pick one thing to fix rather than remove without worrying about backwards compatibility, it would be git-cvsimport. That thing is very badly broken; the engine it uses misplaces branch joins. The Git devs know it’s broken but have stuck to it because of an incremental-conversion feature that I think is effectively useless. They should scrap it and rewrite the CVS import procedure to use cvs-fast-export instead.
What is your favorite Git-related tool/library, outside of Git itself?

You mean other than the ones I’ve written myself? I don’t think I have one, sorry.

Releases

Git 2.26.2 and others, 2.26.1 and others
Git for Windows 2.26.2(1), 2.26.1(1)
libgit2 1.0.0
Gerrit Code Review 3.1.4, 3.0.8
GitHub Enterprise 2.20.5, 2.19.11, 2.18.16, 2.17.22, 2.20.4, 2.19.10, 2.18.15, 2.17.21
GitLab GitLab 12.10, 12.9.4, 12.9.3, 12.8.9, and 12.7.9, 12.9.2, 12.9.1
Bitbucket Server 7.1
GitHub Desktop 2.4.1, 2.4.0
GitKraken 6.6.0

Other News

Various

Peff interviewed Junio on the GitHub Blog to celebrate Git’s 15th anniversary.
An interview with Git creator Linus Torvalds on Git’s 10th anniversary can be found in Git Rev News #2 (April 15th, 2015).
Git credential helper vulnerability announced by Taylor Blau on GitHub Blog – please upgrade to 2.26.2 which fixes the mentioned vulnerability and yet another related vulnerability.
GitHub sharply slashes plan pricing, offers core features for free to all.
GitLab moves 18 features to open source.

Light reading

GitLab: Our ultimate guide to Git. Tagline: “Open source pioneer Git is 15 years old. Here is our guide to making the most of it.”
15 years of Git: How to get started or learn something new by Seth Kenlon (Red Hat) on Opensource.com.
4 Git scripts I can’t live without by Vince Power on Opensource.com. The scripts can be found in the git-extras project.
Optimizing Git For Ryzen CPUs (1.5x Faster), utilizing Intel’s SHA-NI instruction set to speed up SHA-1, by John Sully.
Create web tutorials with Reveal.js and Git by Eric D. Schabell (Red Hat).
Using a self-rewriting README powered by GitHub Actions to track TILs (Today I Learneds) by Simon Willison.
GitOps - A Security Perspective (Part 1) by Gadi Naor of Alcide. GitOps is a paradigm that puts Git at the heart of building and operating cloud native applications by using Git as the single source of truth.
Computer Science Visualized: Useful Git Commands by Lydia Hallie.
How To Make Life Easier When Using Git by Shane Hudson.
A Beginner’s Guide to Git — What is a Changelog and How to Generate it by Gaël Thomas.
Setting Up Git Identities by Micah Henning, with use of a Git alias to switch identities.
Maintaining Different Git Identities by Max Kleucker (2018), with help of Git’s “conditional includes”.
The phases of remote adaptation is a list of phases for teams switching from a colocated environment to a remote one put together by GitLab.

Git tools and sites

Git Extras: shell Git utilities for repo summary, repl, changelog population, author commit percentages and more, by TJ Holowaychuk.
Ovid / git-workflow contains a simplified subset of the git tools used by All Around the World organization.
Dolt is Git for data, versioning tables: a database with branches.
DoltHub is a place on the internet to share Dolt repositories.
GitFiend by Toby Suggate is a new Git client for Windows, Mac and Linux, deliberately not trying to follow in the footsteps of other Git clients.

Credits

Git Rev News Edition 61 (March 25th, 2020)

chriscool — Wed, 25 Mar 2020 11:06:51 +0000

Git Rev News: Edition 61 (March 25th, 2020)

Welcome to the 61st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of February 2020.

Discussions

General

Git Merge 2020 conference

The Git Merge conference happened on March 4, 2020 in Los Angeles. It was organized by GitHub and sponsored by GitHub, GitLab and the Software Freedom Conservancy.

Over 300 people attended. Some people didn’t attend, and some talks had to be changed at the last minute due to coronavirus related reasons.

On the wall a big timeline mentioned some important events in Git history.

There was a party in the evening with a big cake dedicated to Git’s 15th anniversary.
Git Contributor Summit

The Git Contributor Summit happened on March 5, 2020 in Los Angeles, the day after the Git Merge conference. The event was also organized by GitHub.

There were 26 people attending physically and 5 people attending remotely.

As usual it was an unconference where people wrote topics on a whiteboard during the breakfast and then voted on them by putting a tick-mark on the board. The topics were then discussed during the day roughly from the most voted on to the less voted on.

Notes have been taken collaboratively and sent to the mailing list afterwards.
AGit-Flow and git-repo (written by Jiang Xin)

AGit-Flow and git-repo is a blog post on a missing speech from Git Merge 2020. Jiang Xin, a developer at Alibaba China, had planned to speak at the Git Merge 2020 conference, but canceled his flight due to a coronavirus outbreak in China. He wrote this blog post about the topic he wanted to present at the conference.

In this blog post, he introduces a centralized workflow (named AGit-Flow) implemented at Alibaba, and an Open Source command-line tool “git-repo”, which is hosted on GitHub: https://github.com/alibaba/git-repo-go. The tool is not bound to a single protocol or a single server. It is extensible and can run on Gerrit, AGit-Flow or other compatible protocols.

The implementation of AGit-Flow has been contributed to the Git mailing list, and this feature is under code review. Junio stated that the proposed name of the new hook was inappropriate. Therefore, after a code review of these patches, expect some updates on the blog post.

Developer Spotlight: Christian Couder

Who are you and what do you do?

In the Git community I am a contributor since 2006, a member of the PLC (the “Project Leadership Committee” which represents Git in the Conservancy) since a few years ago and a Git Rev News editor since exactly 5 years ago when it started! I also regularly mentor or co-mentor GSoC students or Outreachy interns, and sometimes give presentations about Git at conferences.

My current job title is Senior Backend Engineer in the Gitaly team at GitLab. I have been working full time for GitLab since October last year. Previously since October 2015 I was freelancing for GitLab, Booking.com and Protocol Labs.

I am very happy that GitLab supports my involvement in Git and the Git community. At GitLab I am involved in development activities, and a bit in support, marketing, community relations and sometimes even sales, around Git.

As a hobby I am singing in a choir and with a teacher. I also enjoy time with my 3 teenager kids.
What would you name your most important contribution to Git?

I think the improvements I contributed to git bisect around 2007-2008 helped the Linux kernel community and gave Git an additional edge. At that time it was not clear that Git was going to overcome other version control systems.

Also around 2008 I co-mentored for the first time a GSoC student working on the sequencer which has become more and more useful as it’s now the default underlying engine behind git rebase.

More recently I am happy that my patches to make it possible to have more than one promisor remote have been merged. I think it’s an interesting way to improve performance and to broaden usage.
What are you doing on the Git ecosystem these days, and why?

My time is spent on probably too many different things, like GSoC or Outreachy, Git Rev News, PLC, GitLab activities, improving partial clone, helping with getting GitHub patches merged upstream.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Right now I think it would be a good time to work on specialized drivers/helpers for additional promisor remotes, and on improving partial clone. I am glad though that the main companies contributing to Git have already asked their developers to focus on improving partial clone.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I think I would streamline as much as possible what’s in the Git repo. That is I would remove git-gui, gitk, gitweb, git-svn, git-p4, contrib/ and even the Git test framework, which could perhaps be merged with Sharness. These related tools could live in their own repo but still be discussed on the mailing list and automatically be released at the same time as Git. It would be a significant amount of work to set this up properly, but then new Git related tools, like git-filter-repo or git-subtrac, and perhaps old tools too could probably better find their place in the ecosystem.
What is your favorite Git-related tool/library, outside of Git itself?

In 2016 I became the maintainer of Sharness which was extracted from the Git test framework in 2011. I have thought for a long time that the Git test framework has helped tremendously in keeping the amount of regressions and bugs in Git very low. I don’t have much time to take care of Sharness, but I think it can still help a lot.

Releases

Git 2.26.0, 2.25.2, 2.26.0-rc2, 2.26.0-rc1, 2.26.0-rc0
Git for Windows 2.26.0(1)
Bitbucket Server 7.0
Gerrit Code Review 2.16.17
GitHub Enterprise 2.20.3, 2.20.2, 2.19.9, 2.18.14, 2.17.20, 2.20.1, 2.19.8, 2.18.13, 2.17.19
GitLab 12.9, 12.8.7, 12.8.6, 12.8.5, 12.8.2, 12.8.1, 12.8
GitKraken 6.5.4, 6.5.3, 6.5.2

Other News

Various

Outreachy winter internships finished. Both Heba Waly and Miriam Rubio successfully finished their Outreachy internships. Miriam posted a final blog post about it.
Git has been selected as a Google Summer of Code 2020 mentor organization. Students willing to participate need to apply online until March 31.
Tower for Teachers & Universities: Teachers and universities get free access to Tower “Pro” Git GUI.

Light reading

Derrick Stolee’s slides for his “Git at Scale for Everyone” talk during the Git Merge 2020 conference are available.
Elijah Newren’s slides for his “Scaling the Merge Machinery” talk during the Git Merge 2020 conference are available in his personal notes and presentations repository. Steps to reproduce the speedups he got can be found here.
Graph operations in Git, and how to make them faster presentation slides by Jakub Narębski on SpeakerDeck; also available on SlideShare and as PDF file.
Highlights from Git 2.26 by Taylor Blau on GitHub Blog
Git moves to new defaults in 2.26 release by Julia Schmidt, about version 2 of the transport protocol, backend used by git rebase, etc.
How Git Partial Clone lets you fetch only the large file you need by James Ramsay on GitLab Blog.
Make advanced Git tasks simple with Lazygit: 5 ways to harness the power of git with the Lazygit terminal UI by Jesse Duffield. Lazygit was mentioned in Git Rev News Edition #42 (August 22nd, 2018).
Introducing b4 and patch attestation by Konstantin Ryabitsev. The b4 tool started out as get-lore-mbox; the latter was mentioned in Git Rev News Edition #60 (February 19th, 2020).
- Attestation for kernel patches [LWN.net] by Jonathan Corbet.
Please stop recommending Git Flow! by George Stocker (Git Flow branching model was popularized by blog post entitled A Successful Git branching model).
- The problem with Git flow: Learn why Git flow complicates the lifecycle and discover an alternative to streamline development by Suri Patel on GitLab Blog.
A Beginner’s Guide to Git – How to Write a Good Commit Message by Gaël Thomas.
10 Git Techniques You Need to Know Before You Join a Team by Shaumik Daityari on Sitepoint.
Feature Flags and GitOps. 5 Use Cases to Help You ‘Git’r Done. by Kristin Baskett of CloudBees. The idea of GitOps was mentioned in Git Rev News Edition #42 (August 22nd, 2018) and #43.
Microsoft’s Scalar speeds up Git by Paul Krill in InfoWorld. Scalar was mentioned in Git Rev News Edition #60 (February 19th, 2020).

Git tools and sites

Scalar by Microsoft is a set of tools, settings and extensions for Git to help manage large Git repositories.
bash-git-prompt: an informative and fancy bash prompt for Git users, a port of the “Informative git prompt for zsh”.
showthedocs is a both a syntax highlighter and a documentation browser that finds the relevant docs for your code. Given code, it parses and highlights it, and makes it possible to jump directly to the place in the docs where an item is explained. Includes support for the gitconfig “language”.
//grep.app: Search across a half million git repos, currently public repositories on GitHub; you can search by regular expression, using the RE2 syntax.

Credits

Git Rev News Edition 60 (February 19th, 2020)

chriscool — Wed, 19 Feb 2020 11:06:51 +0000

Git Rev News: Edition 60 (February 19th, 2020)

Welcome to the 60th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of January 2020.

The Pros and Cons of Reposurgeon (written by Eric S. Raymond)

On January 12th 2020, the history of the GNU Compiler Collection was lifted from Subversion to Git. At 280K commits, with a history containing traces of two previous version-control systems (CVS and RCS) this was the largest and most complex repository conversion of an open-source project ever. It swamped the previous record-holder – Emacs’s move from Bazaar to Git back in 2011 – by an order of magnitude.

Both those conversions were done by reposurgeon. Neither of them could practically have been performed by any other conversion tool available. This article will explain why that is, and under what circumstances you might consider using reposurgeon yourself.

Let’s start with a brief description of what reposurgeon actually does. When you use it, you start by reading in a version-control repository… but actually, that’s not quite right. What reposurgeon actually does is read in a git fast-import stream. It looks like it reads repositories because it knows how to call front ends that use exporters such as git-fast-export and cvs-fast-export to serialize a repository for it.

Actually, that’s not quite right either. Subversion doesn’t have an exporter – there is no svn-fast-export (well, not one that works for more than trivial cases, anyway). Instead, reposurgeon reads the native serialization produced by Subversion’s svnadmin dump tool. Internally, this is massaged into the equivalent of a git fast-import stream and represented as one inside reposurgeon.

There are reposurgeon-compatible exporters for RCS, CVS, bzr, hg, SRC, bk, and of course git itself. With a little extra work using sccs2rcs it’s possible to reach all the way back to collections of SCCS files.

Now that you’ve caught your repository, what can you do with it?

I observed earlier that what you have, internally, is a deserialized version of a git fast-input stream. A productive way to think about what reposurgeon does is to remember that this is basically just a DAG (directed acyclic graph) with text attached to the nodes. Now think of reposurgeon as an editor for this graph and its nodes. Then, think of it as a DSL (domain-specific language) designed to be scripted – that is, designed to reproducibly apply editing procedures to this graph.

So the general answer to “what can you do with it” is “anything you want to”. I enjoy thinking about and implementing DSLs, and once I had the basic design idea it was pretty much inevitable that I was going to write the most general set of primitives I could imagine – and I have a very fertile imagination.

Elijah Newren’s aside on reposurgeon in Git Rev News 54 described it as “GDB for history rewriting”. That’s a pretty good analogy, actually. Better than even I knew until recently, because it turns out the Python Cmd library I originally used to write its command interpreter was designed to emulate the interface style of gdb and earlier symbolic debuggers.

Accordingly, you can immediately use reposurgeon for a lot of relatively simple tasks like (1) removing extremely bulky content that shouldn’t have been checked in, (2) partitioning and merging repositories, (3) transcoding Latin-1 metadata to UTF-8, (4) debubbling an unnecessary complex history to make reading it easier.

Often, though, those things can be done with other tools like his git-filter-repo. It’s repository conversions for which you are likely to actually need the full power of a domain-specific language designed for repository surgery.

Which brings us to how you write out your graph as a live repository. Reposurgeon doesn’t do that directly either. When it needs to write out a repository, it hands a git fast-import stream to an importer back end. That could be git fast-import itself, or the corresponding importers for hg, bzr, darcs, bk, RCS, or SRC.

Here’s what reading in and immediately converting a small Subversion dump would look like:

$ reposurgeon
reposurgeon% read <foo.svn
23 svn revisions (0K/s)
* foo
reposurgeon% prefer git
git is the preferred type.
reposurgeon% rebuild bar
reposurgeon: rebuild is complete.
reposurgeon: no preservations.
reposurgeon% 

In theory you now have a Git repository named “bar” in your current directory that is a perfect translation of foo. In practice, for any nontrivial repository, you probably have a bit of a mess on your hands.

If you had read in any Git repository and written it out again, you’d get a perfect copy. But when you’re moving histories between different version-control systems, you have to deal with the mismatch between the source system’s model of version control and the target’s.

A good example of this is the fact that Subversion doesn’t have anything directly corresponding to a Git tag. A Subversion tag is actually a directory copy operation with a target under the tags/ directory. The copy operation leaves a commit in place which, if moved literally to gitspace, would just be junk. What you want is to move the metadata of that commit to an annotated tag.

Many attempts at importers silently botch this in practice, but it can be handled automatically in theory – and reposurgeon does that. The mess you’re likely to have on your hands anyway is due to Subversion operator errors, scar tissue for a previous conversion out of CVS, and use of git-svn as a live gateway to the repository.

The most common symptom of all these error sources is misplaced branch joins; in extreme cases you may even have disconnected branches. Reposurgeon enables you audit for and repair this kind of defect. Here are a few examples of that kind of repair done on the GCC repository:

# /branches/GC_5_0_ALPHA_1
<27855>|<27860> reparent --use-order
# /branches/apple-200511-release-branch
<105446>|<105574> reparent --use-order
# /branches/apple-gcc_os_35-branch
<90334>|<90607> reparent --use-order
# /branches/apple-tiger-release-branch
<96593>|<96595> reparent --use-order

The GCC conversion was pretty hairy – 343 lines of DSL scripting – but there are whole new levels of complexity when, as still sometimes happens, you need to recover history from pre-version-controlled sources to stitch the repository together.

In one extreme case, I ended up stitching together material from 18 different release tarballs, 11 unreleased snapshot tarballs, one release tarball I could reconstruct, one release tarball mined out of an obsolete Red Hat source RPM, two shar archives, a pax archive, five published patches, two zip files, a darcs archive, and a partial RCS history,

But reposurgeon can handle this, because it make conversion experiments easy. The workflow it’s designed for is carefully building a script that assembles your source repository and other data into a simulacrum of what a Git repository tracking your project from the beginning of time would have looked like.

Almost never will you get this right the first time. It takes testing, polishing, tripping over assumptions you didn’t know you and your tools were making, and correcting for those assumptions. In the GCC case it took many hours of work to locate and develop fixes for the misplaced branch joins.

A subtle but important point is that I didn’t do that work myself. That kind of thing is not a job for reposurgeon’s maintainer, it’s a job for a “Mr. Inside” who knows the project’s history intimately – in this case it was actually the GCC project lead, Joseph Myers. One of reposurgeon’s requirements is that it has to be a tool that a “Mr. Inside” can learn to use with minimum friction.

And generally it is, if you’re being driven to it by the kind of problem it was designed to solve – it’s like gdb that way. I’ve been taken to task about the tool having no intro documentation; this is not because I’m lazy, it’s because there’s no plausible way to write any, any more than there is for gdb. You’re ready to learn reposurgeon, as Joseph Myers did, when you’re stuck into a conversion or editing problem so deep that the very complete reposurgeon command reference starts to make sense to you.

You can find more about conversions with reposurgeon here.

Discussions

Support

Broken branch after git commit

Torsten Krah wrote that after using git restore --staged $my-files to remove some files from the index, but not the working tree, and then git commit to commit other changes, he found that the files were marked as deleted in the index though they are still in the working tree.

He didn’t understand what happened and didn’t know how to fix the situation. He later added that the git commit he had done had actually committed the files even though git status told him that the files wouldn’t go into the commit. And he also sent instructions to help reproduce the issue.

Jeff King, alias Peff, replied to Torsten saying that he couldn’t reproduce the issue and asking for more details and examples.

Torsten then sent an example with a lot more details which enabled Peff to reproduce the issue. Peff confirmed that there was a bug in git restore and also found that the index-reading code could segfault when it processes bogus cache-trees.

Peff also mentioned that Emily Shaffer had recently found a similar segfault and that she had provided a fix, and then came up with a patch to fix the bug in git restore --staged.

Junio Hamano, the Git maintainer, reviewed the patch and praised Peff, while Dennis Kaarsemaker reported just being bitten by seemingly the same bug.

In the meantime Torsten also thanked Peff for investigating the issue and asked for a way to fix his current index. Peff suggested using git reset --hard <original-commit> after finding the original commit in the reflog. Torsten replied that he actually had to remove the index using rm .git/index first to get back to a working state.

Developer Spotlight: Chris Webster

Who are you and what do you do?

I am a retired software developer. After 25+ years in commercial software development I wanted to contribute to open source. Having used GNU Make and Perl extensively in a build system I wanted to give back. GitGitGadget caught my attention when I was contributing a fix to diff-highlight.pm in Git. Dscho guided me through my many errors to get the change approved. I decided to help with GitGitGadget to say thanks. Fun/scary facts: Primary language – IBM mainframe assembler, Secondary language: C++.
What would you name your most important contribution to Git?

My contributions are mainly to GitGitGadget and I think adding the /preview command was really helpful. It only gets used once by most new contributors to Git but it gives them a chance to see what their change requests would look like. I hope seeing the email gives these contributors the confidence to submit their changes to the general Git community. It wasn’t a big change but it appears to get used by a lot of first time contributors.
What are you doing on the Git ecosystem these days, and why?

I am still very much in learning mode. Working on GitGitGadget provides an opportunity to work with modern TypeScript and JavaScript features. There are some issues I would still like to help with. Contributing more to Git is a next step. Helping to make tools easier and more reliable is my motivation.
Can you briefly explain your user experience with Git so far?

So far I have been mostly using Git from the command line and only recently started to look at Git-GUI and gitk. This is a stark contrast to my previous use of CM/Synergy and PVCS where the GUI was used almost exclusively. Working on GitGitGadget requires getting to know some of the plumbing of Git and GitHub, which is interesting. For personal projects, most use is pretty basic.
Have you ever felt that something that you’ve used in other version control software is missing from Git?

VS Code shows a side-by-side diff for working objects. CM/Synergy allowed a side-by-side diff for any versions of the objects. I have not seen a way to do that. Sometimes it is easier to debug when you have the complete source to see changes.

Note: Chris was told that git difftool might help him with getting side-by-side diff in Git. He acknowledged the same stating “Difftool looks like what I am looking for”.
What is your favorite Git-related tool/library, outside of Git itself?

My answer should be GitGitGadget but I’m not really a user these days – need to be more of a contributor to Git to appreciate GitGitGadget. VS Code is providing more Git specific tooling (i.e. Timeline view) that looks really interesting along with the GitLens extension.

Releases

Git 2.25.1
GitLab 12.7.6, 12.7.5, 12.7.4, 12.6.6, and 12.5.9, 12.7.2, 12.7
Bitbucket Server 6.10
Gerrit Code Review 3.1.3, 3.0.7, 2.16.16,
GitHub Enterprise 2.20.0, 2.19.7, 2.18.12, 2.17.18, 2.19.6, 2.18.11, 2.17.17
GitKraken 6.5.1, 6.5.0,
GitHub Desktop 2.3.1, 2.3.0
git-cinnabar 0.5.4

Other News

Various

Heads-up for SSH users: as mentioned in the release notes of OpenSSH v8.2, the prevalent ssh-rsa keys will be disabled. If you use SSH with private keys depending on SHA-1, you will want to regenerate them soon.
REBASE: A complete Guide on Rebasing in Git is a new less than 200 pages book from Pascal Precht (with a free sample).

Light reading

The History of Git: The Road to Domination in Software Version Control was made using interviews and material from members of this community, especially Linus Torvalds, Johannes Schindelin and Jeff King.
Transitioning Git to SHA-256:
- A new hash algorithm for Git [LWN.net] by Jonathan Corbet.
- Git takes baby steps towards swapping out vulnerable SHA-1 hashing algo for SHA-256 by Tim Anderson in The Register.
- Bridging the gap: transitioning Git to SHA-256 - Git Merge 2019 video of Brian M. Carlson presentation at Git Merge 2019 (event which was covered in Git Rev News Edition #48 and #49).
Automating MySQL schema migrations with GitHub Actions and more by Shlomi Noach on GitHub Blog, using GitHub-developed gh-ost, an online table migration solution, and skeema by Evan Elias, an open source schema management utility.
Better tools for kernel developers [LWN.net] by Jonathan Corbet, about posting of a simple tool called get-lore-mbox.
In Re: [Lsf-pc] [LSF/MM/BPF TOPIC] FS Maintainers Don’t Scale Dave Chinner writes on the need and usefulness of doing code review, without being experienced in the area that the patch series cover.
Fedora gathering requirements for a Git forge [LWN.net] by Jake Edge, with three possibilities: GitHub, GitLab CE, and Pagure (the last one was mentioned in Git Rev News Edition #24 (February 22nd, 2017)).
‘Succinct Data Structure for Delta Encoding for Modern Databases’ [PDF] or How we built a Git for Data (and Learned to Stop Worrying and Love the Bomb) - whitepaper about TerminusDB.
Lecture 6: Version Control (Git) is a part of “The Missing Semester of Your CS Education” class at MIT.
Weird Hobby: Scraped Git Histories by fREW Schmidt.
How to Bisect Perl on PerlMonks.
Commit Often, Perfect Later, Publish Once: Git Best Practices by Seth Robertson (2012).
🙏 Please Add .gitattributes To Your Git Repository - DEV Community by deadlybyte.
A guide on commit messages - DEV Community by Yvonnick Frin.
Stage. Commit. Push. A Git Story (Comic) - DEV Community by Erika Heidi.
Git Commands – 10 Terminal Tricks Every Developer Should Know by Cem Eygi.

Git tools and sites

git-repo is a reimplementation in Golang by Alibaba Cloud of the Android repo tool.
OneDev is an all-in-one DevOps platform, with issue tracking, Git management, pull requests, and build farm; written in Java.
Introducing Scalar: Git at scale for everyone.
chronologer: visualize changes in program timing (performance) over git commit history; uses hyperfine for the benchmarking.
skeema is an open source pure-SQL database schema management system, with which you can diff, push, and pull schemas.
There are various other tools to help version-control database schemas, including:
- Sqitch is database-native change management for framework-free development and dependable deployment.
- Alembic is a lightweight database migration tool for usage with the SQLAlchemy Database Toolkit for Python.
- Flyway by Redgate, with Apache v2 licensed Community Edition version.
- Liquibase by Datical, with free Liquibase Community edition.
get-lore-mbox by Konstantin Ryabitsev is a Python script that given the message ID for any email in a thread of interest; it will download the entire thread from the lore.kernel.org archive into a local mbox file, for an easy applying to git repository.
GitHub and Government is a site to gather, curate, and feature stories of public servants and civic hackers using GitHub as part of their open government innovations.
git-evtag: Extended verification for git tags, that can be used as a replacement for git-tag -s.
shit (shit == Shell Git) is an implementation of Git [plumbing] using (almost) entirely POSIX shell; more proof-of-concept than a practical tool.
git-tfs is a two-way bridge between TFS and git, similar to git-svn; no more actively maintained because the authors are no longer users of TFS:
- Why you should abandon TFS and adopt Git by Dennis Doomen (2015).

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Eric S. Raymond, Josh Steadmon and Johannes Schindelin.

Git Rev News Edition 59 (January 22nd, 2020)

chriscool — Wed, 22 Jan 2020 11:06:51 +0000

Git Rev News: Edition 59 (January 22nd, 2020)

Welcome to the 59th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened around the month of December 2019.

Discussions

Support

Push a ref to a remote with many refs

Patrick Marlier sent an email about performance issues when pushing from a local repository with a few refs to a remote repository with a lot more refs (1000+) and Git objects.

The local Git client receives the entire list of refs on the remote, and then checks in its repository if the objects exist for all the remote refs, but in Patrick’s case most of the objects are unknown.

As the local repository is using many alternates, Git will try to find each unknown object in all the alternates which amplifies the problem. To work around this Patrick showed a patch that skips the refs that are not part of the push when looking for objects.

Jeff King, alias Peff, replied to Patrick that the behavior is expected and that not looking at the refs which are not part of the push could miss objects that are already in the remote repo, and therefore result in pushing more objects than needed.

Peff proposed an alternative patch that uses an OBJECT_INFO_QUICK flag when checking if objects exist. That flag makes the check faster but less thorough, which is ok in this case.

Patrick then thanked Peff for the patch saying that he would try it, and later replied with some numbers showing a median time decreasing from 7 minutes and 38 seconds to 5 minutes and 40 seconds. Peff replied to those numbers suggesting applying the patch to Git 2.21 or higher, instead of Git 2.19, as a memory cache was introduced in 2.21 that would further speed up the checks.

In general it’s a good idea to always use the most recent Git version for maximum performance as improvements are regularly merged into each new version.

Meanwhile Junio Hamano, the Git maintainer wondered if improvements could be made regarding the different flags that can be used when checking objects. Peff replied that these flags have been coming up in discussions “about once a month lately” and pointed to a previous analysis made by Jonathan Tan. He also suggested some small changes in the flags according to the analysis.

Jonathan Tan then chimed in to give his opinion about the flag issue and mostly agreed with Peff’s suggestion. Junio then also agreed with Peff’s and Jonathan’s findings.

Jonathan Nieder reviewed Peff’s patch asking a few questions to make sure he understood it properly. Peff then answered those questions explaining a few more details.

Peff’s patch eventually got merged into the master branch and is included in the recent Git 2.25 release.

Releases

Git 2.25.0, 2.25.0-rc2, 2.25.0-rc1, 2.25.0-rc0
Git for Windows 2.25.0(1)
GitHub Enterprise 2.19.5, 2.18.10, 2.17.16, 2.16.25
GitLab 12.6.4, 12.5.7, and 12.4.8, 12.6.3, 12.6.2, 12.5.6, and 12.4.7, 12.6.1
Bitbucket Server 6.10

Other News

Various

Registration for the Git Contributor Summit, on March 5, 2020, at Los Angeles is now open.
Highlights from Git 2.25 by Taylor Blau on GitHub Blog
Git team releases 2.25, takes step towards Perl freedom by Julia Schmidt

Light reading

Bring your monorepo down to size with sparse-checkout by Derrick Stolee on GitHub Blog
Stage. Commit. Push. A Git Story (Comic) by Erika Heidi
6 handy Bash scripts for Git by Bob Peterson: gitlog, gitlog.id, gitlog.grep, gitbranchcmp, gitlog.find,…
git switch <branch> – Easily checkout git branches with this new command by Irshad Bluecast
Git tips for trunk-based development by Alessandro Diaferia
Understanding delta file changes and merge conflicts in Git pull requests by Aram on Azure DevOps Blog

Git tools and sites

git-filter-repo v2.25.0 has been announced on the mailing list.
git-cinnabar 0.5.3 has also been announced on the mailing list.
GitVine by Insane Sharpness: A simpler visualisation of Git Commits, inspired by Clearcase Version Tree. Not open-source.
GitAhead is a graphical Git client for Windows, Linux and macOS designed to help you understand and manage your source code history, by SciTools™.

Credits

Git Rev News Edition 58 (December 25th, 2019)

chriscool — Wed, 25 Dec 2019 11:06:51 +0000

Git Rev News: Edition 58 (December 25th, 2019)

Welcome to the 58th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of November 2019.

Discussions

General

Two Outreachy interns have been accepted to work on Git this winter
- Heba W. from New Zealand will be mentored by Emily Shaffer and Jonathan Tan to work on the ‘Add “Did you mean?” hints’ project. Heba started blogging about her internship.
- Miriam Rubio from Barcelona, Spain will be mentored by Christian Couder to work on the ‘Finish converting “git bisect” from shell to C’ project. Miriam also started blogging about her internship.

Reviews

[RFC] xl command for visualizing recent history

Matthew DeVore sent an RFC patch implementing a git xl command that would show “a graph of recent history, including all existing branches (unless flagged with a config option) and their upstream counterparts”.

In practice the command would show graph like this one, where the XXXXXXXX would be the beginning of a commit hash:
```
XXXXXXXX  *  1   committer@example.com  [HEAD branch3]
          | baz
          |
XXXXXXXX  | *  2   committer@example.com  [branch2]
          |/  bar
          |
XXXXXXXX  *  3   committer@example.com
            foo
```
The command would also associate refs with all visible commits. These refs would have names in the form of h/# where # is an incrementing count.

It would by default show only what has not been pushed upstream yet, and the branches with their commits would be shown as a graph.

Emily Shaffer first replied to Matthew, making suggestions to improve the name of the command as well as the commit subject and the commit message.

Johannes Schindelin, alias Dscho, replied to Emily’s reply. He agreed with her that the name of the command was not a good one and suggested instead to make this functionality a mode of an existing command, like git show-branch --unpushed or git branch --show-unpushed.

About the h/# refs, that he called “ephemeral refs”, Dscho suggested implementing them in a separate patch, using ^<counter> instead of “h/#” for their syntax, and making them only available for a “reasonably short time” by default, and then offering a config setting to change this time.

He also suggested implementing an option to show those “ephemeral refs” in other commands too.

Phillip Wood agreed with Dscho about the “ephemeral refs”, especially “having them as a feature of the rev listing machinery rather than specific to a particular command”. He also suggested to use getsid() rather than getppid() to tie them to a terminal, and expressed his uncertainty how this should be done on Windows and whether a split was also necessary/wanted per worktree.

Dscho also commented on Matthew’s initial RFC patch. He suggested commit message improvements. He reiterated some of the suggestions he made in his reply to Emily, and reviewed the code suggesting many changes there too. He wrote though that he loved the main ideas proposed by Matthew.

Releases

Git 2.24.1 and others
Git for Windows 2.24.1(2)
libgit2 0.28.4
libgit2sharp 0.26.2
Bitbucket Server 6.9
Gerrit Code Review 3.1.2, 3.0.6, 2.16.15, 3.1.1, 3.0.5, 2.16.14
GitHub Enterprise 2.19.4, 2.18.9, 2.17.15, 2.16.24, 2.19.3, 2.18.8, 2.17.14, 2.16.23, 2.19.2, 2.18.7, 2.17.13, 2.16.22
GitLab 12.6, 12.5.5, 12.0.12, 12.1.17, and 12.2.12, 12.5.4, 12.4.6, and 12.3.9, 12.5.3, 12.5.1, 12.5.2, 12.5, 12.4.3
GitKraken 6.4.1, 6.4.0
GitHub Desktop 2.2.4

Other News

Various

The latest Git releases and Git for Windows releases are security releases. They fix a significant number of serious security issues. Upgrading to one of these new versions is highly recommended.
The Git Merge Contributor’s Summit has been announced. It will happen on March 5, 2020, in Los Angeles, the day after the Git Merge.

Light reading

What are git objects under the hood is a blog post about Git objects.
Git Repository Transfer Keeping All History by Nassos Michas explains “how to replicate your Git repo and keep all previous commits, branches, and tags”.

Git tools and sites

GitVine, an application to better visualise git commits has been announced on the mailing list.
git-cpcover, a script to copy cover letters, has been announced on the mailing list.

Credits

Git Rev News Edition 57 (November 20th, 2019)

chriscool — Wed, 20 Nov 2019 11:06:51 +0000

Git Rev News: Edition 57 (November 20th, 2019)

Welcome to the 57th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of October 2019.

Discussions

General

RFC: Moving git-gui development to GitHub

Pratyush Yadav, a new maintainer for git-gui, asked about whether it is a better idea to use GitHub for development instead of email (after discussion with Dscho), stating arguments in favor and against of moving to GitHub. There were some voices for the idea, and some against, describing additional advantages and disadvantages. One idea was to use GitHub Issues as a centralized issue / bug tracker regardless of where development would take place, which Yadav did.

An interesting vote against the idea was that of Elijah Newren, who wrote that he had been pondering asking the opposite question for filter-repo, i.e. moving its development to git mailing list.

Reviews

[PATCH 0/9] [RFC] New sparse-checkout builtin and “cone” mode

Last August, Derrick Stolee, who prefers to be called just “Stolee”, sent to the mailing list an RFC patch series to “make the sparse-checkout more user-friendly” and to increase performance in very large repositories.

The patch series achieves that by introducing a new git sparse-checkout command with 4 subcommands: init, add, list and disable. The series also introduces the --sparse option to git clone.

This helps users manipulate how a sparse-checkout is performed compared to the current way.

The performance boost is achieved through a new mode called “cone mode” where all the patterns in the sparse-checkout file are “based on prefix matches at a directory level”. In this mode it can be faster to match the patterns to the files and directories that should or should not be checked out, because a hashset (a set implemented using a hash table) can be used.

Elijah Newren reviewed Stolee’s patches. As Stolee had mentioned that some people have created their own helper tools, Elijah first revealed that he also created a “sparsify” script specific to his company’s internal repository.

Elijah then was concerned about how the feature worked along with worktrees and how the add subcommand and the cone mode worked. He suggested that the core.sparseCheckout config option could be tri-state to make it explicit how the sparse-checkout file should be parsed.

Eric Sunshine also chimed into the discussion.

Stolee replied to Elijah that he hadn’t considered worktrees and was going to take a look at them. He accepted the suggestions about how add should work and about making core.sparseCheckout a tri-state and then sent a V2 version of the patch series with those changes and a few other improvements.

The add subcommand was also replaced with a set subcommand, and the tri-state was actually implemented by adding a new core.sparseCheckoutCone config option.

The discussion continued between Stolee and Elijah, mostly about the documentation and commit messages. Then Stolee sent a V3 version of the patch series with small bug fixes and various improvements, especially in the documentation and commit messages according to Elijah’s suggestions.

After another round of review from Elijah, Stolee sent a V4 version of the patch series with only a few small changes.

Then Gábor Szeder commented on few bugs and small things he had found; Jon Simons and Elijah also made a few comments. So Stolee sent a V5 version of the patch series on October 21st addressing the comments.

Phillip Wood, Stolee and Junio Hamano then discussed another small issue. It seems though that the patch series will be merged into the next branch soon.

Developer Spotlight: Phillip Wood

Who are you and what do you do?

I’m a physicist by training, unfortunately I had to stop working some years ago due to a chronic health condition. Since then I’ve spent some time coding and I got into contributing to Git after using it on another open source project.
What would you name your most important contribution to Git?

That’s hard to say. Personally it was getting rebase -i to create commits without forking git commit. I think it was my first big contribution, it gave a noticeable performance improvement and meant learning the API around commit creation as well as getting to grips with the sequencer code that drives cherry-picks and interactive rebases.
What are you doing on the Git project these days, and why?

I’m still mostly working around the code in the sequencer. Interactive rebases are one of the features I like best about Git. Being able to rewrite commits in order to polish a feature before merging it or posting patches helps make it easier to understand and review. I’ve also contributed to add -p and diff --color-moved-ws as I find those really useful as well.

I also try to spend some time reviewing patches in the areas I’m interested in. One of the great things about contributing to Git is the reviews one receives when posting patches, they’re always friendly and constructive and I try to do the same for others. It’s also interesting to see what problems other people who use Git are facing and how they’re solving them.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Gosh that would be fantastic. I’d probably concentrate on the UI. Firstly I’m interested in being able to amend commits more easily by providing a simpler interface to rebase -i that does not involve editing a todo file. I’m currently working on a script that lets you amend the commit that created the current line directly from an editor and lets you walk backwards and forwards through history rewriting it as you go. Being able to say “amend the commit responsible for this line” with a single key stroke is really convenient.

There are a number of other UI related projects I’m interested in. I use diff-highlight but wish it would work on hunks with different numbers of additions and deletions. Adapting it to diff the diff in order to highlight the changes would be useful but would need some careful heuristics to distinguish between when highlighting the changes is useful and when it is just confusing. Another diff improvement I’d like to see is implementing --color=porcelain for git diff that would allow apps like tig and magit to show moved lines.

I’d also like to improve git push and git pull to extend the idea of --force-with-lease to support synchronizing between a laptop, desktop and remote server by allowing forced updates of the local branch when it has not changed since it was last pushed and improve push --force-with-lease to default to using the hash of the last pushed commit.

If there’s still some time left then working on the documentation to make it more approachable for new users would be great. At the moment the man pages detail the individual commands but there’s not much documentation introducing high level concepts and ideas. There are some other things such as adding a --reword option to commit and improving add -p to allow the selection of groups of lines but that’s probably enough for now.
If you could remove something from Git without worrying backwards compatibility, what would it be?

Personally I’d like to change the way ignored files are handled so that Git never overwrites them (we could add a new category for files that are expendable). The relative priority of .gitignore and .git/info/excludes could also be tweaked.

Standardizing option names across the commands would also help users I think.
What is your favorite Git-related tool/library, outside of Git itself?

I use tig for inspecting history with log and blame. I also use Public Inbox a lot for searching the mailing list.

Releases

Git 2.24.0, 2.24.0-rc2, 2.24.0-rc1
Git for Windows 2.24.0(2), 2.24.0(1)
GitLab 12.4.2, 12.4.1
Bitbucket Server 6.8
Gerrit Code Review 3.1.0, 3.0.4, 2.16.13, 2.15.18
GitHub Enterprise 2.19.1, 2.19.0, 2.18.6, 2.17.12, 2.16.21, 2.18.5, 2.17.11, 2.16.20
TortoiseGit 2.9.0
GitKraken 6.3.1
GitHub Desktop 2.2.3, 2.2.2

Other News

Various

Welcome to Kaartic Sivaraam to the Git Rev News edition team! And thanks to Gabriel Alcaras, who leaves the team after contributing to the interviews and as the author of the script that scrapes some websites to help prepare the “Releases” section.
Emily Shaffer announced the new git-mentoring@googlegroups.com mailing list as “a great place for those who are new to Git and interested in learning how to contribute to ask questions and expect kind, thorough answers out of the spotlight of the main Git mailing list”.
GitHub announced GitHub Archive Program, intended to preserve open source software for future generations in partership with Long Now Foundation, the Internet Archive, the Software Heritage Foundation, Arctic World Archive, Microsoft Research, the Bodleian Library, and Stanford Libraries. On February 2, 2020, GitHub will capture a snapshot of every active public repository, to be preserved in the GitHub Arctic Code Vault. This data will be stored on 3,500-foot film reels.
It looks like the Git Merge 2020 conference will be in Los Angeles on March 4 2020.

Light reading

Highlights from Git 2.24 on GitHub Blog by Taylor Blau: feature macros, commit graph by default, adopting the Contributor Covenant (see previous Git Rev News), recommending new history-rewriting tool: git-filter-repo (more about which can be found in Git Rev News #54), and other.
Updates to the Git Commit Graph Feature by Derrick Stolee describes new commit-graph related changes in Git version 2.24.0: new faster algorithm for topological sorting (e.g. for git log --graph), namely an iterative version of Kahn’s algorithm (making use of generation numbers), incremental commit-graph format with adaptive merging, new fetch.writeCommitGraph setting to update commit-graph after every git fetch, and having core.commitGraph and gc.writeCommitGraph on by default. See also this Twitter thread.

Previous blog posts in the series about commit-graph were linked to in Git Rev News Edition #41, #45 and #51. Developing incremental commit-graph was covered in detail in Git Rev News Edition #52. At the time of writing link to mentioned article was not yet posted to Derrick Stolee developer homepage.
[LWN.net] Next steps for kernel workflow improvement by Jonathan Corbet: fix attestation with minisig, add base-tree information, and going beyond email.
[LWN.net] Analyzing kernel email by Jake Edge, about research which goal is “formalizing and assessing the Linux kernel development process”.
I posted my password / API key on GitHub. Now what? by Flavio Copes. There are various tools to detect such situation, and/or to safely store secrets in Git repository; some links can be found for example in Git Rev News #39.
Three Simple Rules for Putting Secrets into Git by Jesse Swidler (2018), author of LockGit.
“Stupid git commit-tree tricks” series of blog posts by Raymond Chen, starting with Part 1: Building a commit manually out of a tree.
My favourite Git commit by David Thompson.
How to write a kickass README by James.Scott (@scottydocs).
What nobody tells you about documentation, namely that it needs to include and be structured around its four different functions: tutorials, how-to guides, explanation and technical reference, each of which requires a distinct mode of writing.

Git tools and sites

Git Graph extension for Visual Studio Code – view a commit graph of your repository, and easily perform Git actions from the graph.
git-subtrac is a helper tool that makes it easier to keep track of your git submodule contents. It collects the entire contents of the entire history of all your submodules (recursively) into a separate git branch, which can be pushed, pulled, forked, and merged however you want. Announced as a sequel to git-subtree by Avery Pennarun, creator of git-subtree.
myrepos is a tool to manage all your version control repositories, for example to update them all at once, or push out all your local changes (similar to git-repo or gitslave tools).
LockGit is a CLI tool for storing encrypted secrets in a git repo.
Onefetch is a command line tool that displays summary information about your Git repository directly on your terminal.
USA-Constitution repository, with a history of edits to the US Constitution as it has been amended. Written in Markdown to match original formatting.
Gitter is an open-source instant messaging and chat room system for developers and users of GitHub repositories, similar to Slack. Gitter is provided as software-as-a-service.
.gitignore Generator extension for Visual Studio Code - easily and quickly generate .gitignore file for your project. It uses the gitignore.io API.

Credits

Git Rev News Edition 56 (October 26th, 2019)

chriscool — Sat, 26 Oct 2019 11:06:51 +0000

Git Rev News: Edition 56 (October 26th, 2019)

Welcome to the 56th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of September 2019.

Discussions

General

Growing the Git community

Derrick Stolee, who prefers to be called Stolee, emailed the mailing list after the Virtual Contributor Summit (see previous edition) saying he wanted to further discuss some ideas, that had been shared during the Summit, about “Inclusion & Diversity” with the goal of making the community more welcoming to new contributors of all kinds.

He listed some possible problems that could prevent new contributors entering the community:
1. Discovering how to contribute to Git is non-obvious.
2. Submitting to a mailing list is a new experience for most developers. This includes the full review and discussion process.
3. The high standards for patch quality are intimidating to new contributors.
4. Some people do not feel comfortable engaging in a community without a clear Code of Conduct. This discomfort is significant and based on real experiences throughout society.
5. Since Git development happens in a different place than where users acquire the end product, some are not aware that they can contribute.
Then Stolee proposed actions to address the problems:
1. Improve the documentation for contributing to Git.
2. Add more pointers to GitGitGadget.
3. Introduce a new “mentors” mailing list.
4. Add an official Code of Conduct.
5. Advertise that Git wants new contributors.
Each action was explained and justified, sometimes pointing to interesting research like the recent paper "”We Don’t Do That Here”: How Collaborative Editing With Mentors Improves Engagement in Social Q&A Communities”.

Stolee also proposed some metrics to be measured between releases to monitor how the community are doing:
1. How many first-time contributors sent a patch?
2. How many contributors had their first commit accepted into the release?
3. How many contributors started reviewing?
4. How many total patches/reviews did the list receive?
His email was very detailed with many suggestions about how to implement the actions, and he asked interesting questions to gather peoples’ opinion.

Denton Liu replied to Stolee sharing some thoughts as a “relatively new contributor (just less than a year)”. He said that from his experience to get more contributors, we should try to answer the “how do we make it more fun to contribute to Git?” question.

He recalled that most of his time learning to contribute to Git “stemmed from the fact that there’s a lot of tribal knowledge that’s not really written down anywhere”.

As Stolee had mentioned the “My First Contribution” document, which was recently contributed by Emily Shaffer, Denton said that it would have really helped him get started.

Denton also suggested improving transparency about what happens to patches sent to the mailing list.

Mike Hommey replied to Stolee suggesting an additional problem which is that newcomers don’t really have any idea what they could contribute.

Johannes Schindelin, alias Dscho, replied to Mike that newcomers need experienced developers to validate the ideas they would like to implement in Git, before they can be confident enough to work on them. And they also need to be shown ideas they could implement. Dscho then talked about the GitGitGadget issue list which is open and “intended to accumulate possible project ideas”. Dscho also acknowledged the Chromium Git issue list which is another issue tracker with a similar purpose.

Replying to Stolee, Jeff King, alias Peff, who is responsible for the main Git web site, suggested improving the community page to add more information for beginners. He said he was open to accepting patches or pull requests.

Elijah Newren mostly agreed with Stolee’s email, but suggested a less strongly worded tone when talking about goals and existing problems.

Junio Hamano, the Git maintainer, replied to Stolee about the goal of the project and the metrics that we could use with the following:

We first should make sure that we serve existing users and existing community members well. So well that other people who are not yet our “existing” users and members would want to become part of us, in order to join the fun and share the benefit. If we cannot serve even the existing members well, we shouldn’t be talking about acquiring new members.

He then proposed to measure “community-member happiness” with metrics like “This many percent of total community member population have been active this month”.

The discussion involved a number of other Git developers like Jakub Narębski, Emily Shaffer, Garima Singh, Pierre Tardy, Philip Oakley and Randall S. Becker.

A number of people commented especially on the subject of adding an official Code of Conduct, which will be reported on in a separate article below.

Otherwise it remains to be seen if many actions will be taken to make the project more welcoming to new contributors.
[PATCH] add a Code of Conduct document

Following the Virtual Contributor Summit (see previous edition) and the discussions about growing the Git community (see the article above), Jeff King, alias Peff, decided to send a patch to add a code of conduct.

In his patch he says that “it may be a good time to cement our expectations when things are quiet, since it gives everybody some distance rather than focusing on a current contentious issue”. Many people indeed agreed in the previous discussions with that point of view, and the idea of a Code of Conduct in the first place.

Peff says that his patch adapts the Contributor Covenant Code of Conduct from https://www.contributor-covenant.org/version/1/4/code-of-conduct.html and that “it’s also the same document used by the Git for Windows project”.

One of the changes is that for dealing with community issues, the document spreads the responsibility to the Project Leadership Committee (git@sfconservancy.org) instead of the only maintainer, Junio C Hamano.

Peff also mentioned a commit by Michael Haggerty from June 2013 that he found in a previous discussion and that has nice set of guidelines about how to review code.

A number of the replies were about the Project Leadership Committee as it’s not easy to know who is part of it. This was acknowledged by Peff who sent a follow-up patch to address the issue by listing the Project Leadership Committee members with their email addresses and by saying that they can also be contacted individually.

Even though there was some disagreement, in general most of the people taking part in the discussion agreed with Peff’s patches. Junio later sent a follow-up email with the subject “Raise your hand to Ack jk/code-of-conduct if your Ack fell thru cracks” to get more developers to formally agree with the final patch, which then several did.

The commit adding the Code of Conduct has since been merged into the master branch.

Releases

Git 2.24.0-rc0
Git for Windows 2.24.0-rc0
GitHub Enterprise 2.18.4, 2.17.10, 2.16.19, 2.15.24, 2.18.3, 2.17.9, 2.16.18, 2.15.23
GitLab 12.4, 12.3.5, 12.2.8, and 12.1.14, 12.3.4, 12.3.3, 12.2.7, and 12.1.13, 12.3.2, 12.2.6, and 12.1.12, 12.3.1, 12.3
Bitbucket Server 6.7
Gerrit Code Review 3.0.3
GitKraken 6.3.0, 6.2.1
GitHub Desktop 2.2.1, 2.2.0

Other News

Various

A new maintainer for Git-Gui, Pratyush Yadav (@prati0100), came forward. Let’s praise and thank him for volunteering.
The Gerrit User Summit 2019 is going to be broadcasted on live.gerritforge.com and will include talks about JGit and Gerrit Code Review, including major members of the Git Community, like Jonathan Nieder and Terry Parker.

Light reading

Commit graph drawing algorithms by pvigier (Pierre Vigier), describes algorithms used by various tools including one in pvigier’s prototype git client called gitamine.
Git Pathspecs and How to Use Them by Adam Giese.
GitHub Actions, the missing notes: CMake, Qt and IFW by Michele ‘skypjack’ Caini, shows how he uses GitHub Actions in his project. (GitHub Actions, still in public beta, were first covered in Git Rev News #44)
An Unintentionally Comprehensive Introduction to GitHub Actions CI by Tierney Cyren – with example of an application build on top of Node.js.
Scheduling Jekyll posts with Netlify and GitHub Actions by Nicholas C. Zakas on his Human Who Codes blog: using a GitHub Action cron job to schedule Netlify builds for static site generated blog posts (which was previously done using Netlify and AWS Lambda).
“git request-pull” and confusing diffstats [LWN.net] by Jonathan Corbet talks about what to do if the history to be pulled includes merges from outside (e.g. to obtain the dependencies for a fix), and why it happens.
How Bash completion works and Adding Bash completion to my tool by Chris Patuzzo; Git’s Bash completion can be found in contrib/completion/git-completion.bash.

Git tools and sites

Gollum is a simple, Git-powered wiki written in Ruby with a sweet API and local frontend.
git_examples.sh – 99% of the Git commands you’ll need at work, demonstrated in a single script.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from Emily Shaffer, Luca Milanesio and George Espinoza.

Git Rev News Edition 55 (September 25th, 2019)

chriscool — Wed, 25 Sep 2019 11:06:51 +0000

Git Rev News: Edition 55 (September 25th, 2019)

Welcome to the 55th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of August 2019.

Discussions

General

Google Summer of Code 2019 is over.

Both students, Rohit Ashiwal and Matheus Tavares, passed their final evaluation and posted a final report on their blog. See:
- Rohit’s report about improving the consistency of sequencer commands
- Matheus’ report about making pack access code thread-safe
Virtual Git Contributor Summit

Johannes Schindelin, alias Dscho, organized the first Virtual Git Contributor Summit which happened on Thursday September 12 and Friday September 13 over a Zoom call.

Notes (plain text) have been taken and are used to organize follow up actions.
RFC - Git Developer Blog

Emily Shaffer asked on the mailing list if people would be interested in creating a “Git-project-blessed blog written by Git contributors”. The goal was “to make Git better understood in the rest of the world”, in a not very formal setting.

A number of people replied to Emily saying that they thought it was a good idea, and sometimes agreeing to submit articles for the new blog or to review other people’s submissions.

Jeff King, who manages the git-scm.com web site, suggested hosting it at the same place using blog.git-scm.com, which Emily accepted.

Following the Virtual Git Contributor Summit a repository has been created for the blog by James Ramsay.

Support

diff.renames not working?

Robert Dailey wondered if the diff.renames config option worked correctly when it’s set to copies, as git diff --name-status and git diff --follow (which is not documented) showed that one file was copied from another when they were passed a path to a file as argument, but git diff and git diff -M didn’t.

Jeff King, alias Peff, replied to Robert explaining how rename detection works and what are the current limitations. He also suggested some possible improvements.

Bryan Turner and Peff also noticed that -M detects renames, not copies.

Junio agreed with Peff and gave extra historical information and also discussed possible improvements.

Developer Spotlight: Emily Shaffer

Who are you and what do you do?

I’m a California resident, dog mom, maker, and software engineer at Google contributing to Git as my day job!
What would you name your most important contribution to Git?

The My First Contribution tutorial - it’s helping folks who are interested in committing to Git full-time figure out how to write and send patches, and more importantly (to me), it has launched a conversation about better internal documentation for Git contributors, which I’m really excited about.
What are you doing on the Git project these days, and why?

Lately, I’ve been making it easier for the Git team at Google to distribute Git to Googlers (gee). For the benefit of the broader community, I have started working on a tool to help users generate helpful, actionable bug reports. Soon I hope to be doing some work with hook management.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Submodules! I think they’re such a cool idea but they have a long way to go right now. It’s a little personal for me; I also contribute to OpenBMC which I think could benefit a lot from using submodules as well, but it hasn’t been feasible yet.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

That’s a good question! There are lots of depths of Git that I haven’t been subjected to yet, so I think I have to do some more homework before I can decide what I’d do away with.
What is your favorite Git-related tool/library, outside of Git itself?

Probably the high number of tiny .bashrc aliases I’ve got for the Git CLI. My work would be much slower without quick aliases for git grep, git format-patch, and so on. Or, I suppose related to the Git project (but not the Git tool), I learned to use mutt for interacting with the Git mailing list and am still thrilled to be able to email in Vim.

Releases

Gerrit Code Review 2.16.12, 2.15.17, 3.0.2
GitHub Enterprise 2.18.2, 2.17.8, 2.16.17, 2.15.22, 2.18.1, 2.17.7, 2.16.16, 2.15.21
GitLab 12.3, 12.1.11, 12.2.5, 12.1.9, and 12.0.9, 12.2.4, 12.2.3, 12.2.1
Bitbucket Server 6.6
GitKraken 6.2.0, 6.1.4, 6.1.3, 6.1.2, 6.1.1, 6.1.0, 6.0.1, 6.0.0
GitHub Desktop 2.1.3

Other News

Various

Highlights from Git 2.23 on GitHub blog by Taylor Blau.
There is an informal Git standup on IRC on #git-devel on irc.freenode.net every two weeks; you can find dates in Git Events calendar (.ics); logs are at https://j.mp/gitdevlog.
Sunsetting Mercurial support in Bitbucket.

Light reading

“They Didn’t Teach Us This”: A Crash Course for Your First Job in Software by Max Pekarsky, which includes Git Workflow section.
First Steps Contributing to Git by Matheus Tavares, GSoC 2019 student.
Maintaining the kernel’s web of trust [LWN.net] by Jonathan Corbet; one of the proposed solutions is to use pgpkeys.git repository to hold GPG keys for kernel developers.
Defragmenting the kernel development process [LWN.net] article by Jonathan Corbet, including section about version control and Git. It mentions and references Change IDs for kernel patches [LWN.net].
GitLens: where have you been all my life! by G.L Solaria, told using animated screenshots GIFs. GitLens add-on for Visual Studio Code was mentioned in Git Rev News Edition #48.
Git Can Do That? Git presentation given at Web Weekend Kathmandu, 2019 by Pratik Karki.

Git tools and sites

patchew is a patch email tracking and testing system, very similar to patchwork (mentioned in Git Rev News Edition #20).
gitin2it, set of [git] aliases to make git actions more intuitive.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from Emily Shaffer, James Ramsay, Pratik Karki and Thomas Ferris.

Git Rev News Edition 54 (August 21st, 2019)

chriscool — Wed, 21 Aug 2019 11:06:51 +0000

Git Rev News: Edition 54 (August 21st, 2019)

Welcome to the 54th edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of July 2019.

An Introduction to git-filter-repo (written by Elijah Newren)

There is a new tool available for surgery on git repositories: git-filter-repo. It claims to have many new unique features, good performance, and an ability to scale – from making simple history rewrites trivial, to facilitating the creation of entirely new tools which leverage existing capabilities to handle more complex cases.

You can read more about common use cases and base capabilities of filter-repo, but in this article, I’d like to focus on two things: providing a simple example to give a very brief flavor for git-filter-repo usage, and answer a few likely questions about its purpose and rationale (including a short comparison to other tools). I will provide several links along the way for curious folks to learn more.

A simple example

Let’s start with a simple example that has come up a lot for me: extracting a piece of an existing repository and preparing it to be merged into some larger monorepository. So, we want to:

extract the history of a single directory, src/. This means that only paths under src/ remain in the repo, and any commits that only touched paths outside this directory will be removed.
rename all files to have a new leading directory, my-module/ (e.g. so that src/foo.c becomes my-module/src/foo.c)
rename any tags in the extracted repository to have a ‘my-module-‘ prefix (to avoid any conflicts when we later merge this repo into something else)

Doing this with filter-repo is as simple as the following command:

  git filter-repo --path src/ --to-subdirectory-filter my-module --tag-rename '':'my-module-'

(The single quotes are unnecessary, but make it clearer to a human that we are replacing the empty string as a prefix with my-module-.)

By contrast, filter-branch comes with a pile of caveats even once you figure out the necessary (OS-dependent) invocation(s):

  git filter-branch \
      --index-filter 'git ls-files \
			  | grep -v ^src/ \
			  | xargs git rm -q --cached; \
		      git ls-files -s \
			  | sed "s%$(printf \\t)%&my-module/%" \
			  | git update-index --index-info; \
		      git ls-files \
			  | grep -v ^my-module/ \
			  | xargs git rm -q --cached' \
      --tag-name-filter 'echo "my-module-$(cat)"' --prune-empty -- --all
  git clone file://$(pwd) newcopy
  cd newcopy
  git for-each-ref --format="delete %(refname)" refs/tags/ \
      | grep -v refs/tags/my-module- \
      | git update-ref --stdin
  git gc --prune=now

BFG is not capable of this type of rewrite, and this type of rewrite is difficult to perform safely using fast-export and fast-import directly.

You can find a lot more examples in filter-repo’s manpage. (If you are curious about the “pile of caveats” mentioned above or the reasons for the extra steps for filter-branch, you can read more details about this example).

Why a new tool instead of contributing to other tools?

There are two well known tools in the repository rewriting space:

and two lesser-known tools:

(While fast-export and fast-import themselves are well known, they are usually thought of as export-to-another-VCS or import-from-another-VCS tools, though they also work for git->git transitions.)

I will briefly discuss each.

filter-branch and BFG

It’s natural to ask why, if these well-known tools lacked features I wanted, they could not have been extended instead of creating a new tool. In short, they were philosophically the wrong starting point for extension and they also had the wrong architecture or design to support such an effort.

From the philosophical angle:

BFG: easy to use flags for some common cases, but not extensible
filter-branch: relatively versatile capability via user-specified shell commands, but rapidly becomes very difficult to use beyond trivial cases especially as usability defaults increasingly conflict and cause problems.

I wanted something that made the easy cases simple like BFG, but which would scale up to more difficult cases and have versatility beyond that which filter-branch provides.

From the technical architecture/design angle:

BFG: works on packfiles and packed-refs, directly rewriting tree and blob objects; Roberto proved you can get a lot done with this design with his work on the BFG (as many people who have used his tool can attest), but this design does not permit things like differentiating paths in different directories with the same basename nor could it be used to allow renaming of paths (except within the same directory). Further, this design even sadly runs into a lot of roadblocks and limitations even within its intended use case of removing big or sensitive content.
filter-branch: performance really shouldn’t matter for a one shot usage tool, but filter-branch can turn a few hour rewrite (allowing an overnight downtime) into an intractable three-month wait. Further, its design architecture leaks through every level of the interface, making it nearly impossible to change anything about the slow design without having backward compatibility issues. These issues are well known, but what is less well known is that even ignoring performance, the usability choices in filter-branch rapidly become increasingly conflicting and problematic for users with larger repos and more involved rewrites, difficulties that again cannot be ameliorated without breaking backward compatibility.

reposurgeon

Some brief impressions about reposurgeon:

Appears to be almost exclusively focused on transitioning between different version control systems (CVS, SVN, Hg, Bazaar, Git, etc.), and in particular handling the myriad edge and corner cases that arise in transitioning from CVS or SVN to a DVCS.
Provides very thorough reference-style documentation; if you read all reposurgeon documentation, you will likely feel as though you can take an existing example and modify it in many ways.
Absolutely no full-fledged examples or user-guide style documentation are provided for getting started.
Appears to not have any facilities for quick (in terms of time spent by the user) conversions similar to filter-branch, BFG, or filter-repo. Users who want such capabilities are likely to be frustrated by reposurgeon and give up.
Strikes me as “GDB for history rewriting”; it has lots of facilities for manually inspecting and editing, but is not intended for the first-time or casual history spelunker. Only those who view history spelunking as a frequent hobby or job are likely to dive in. And it’s not quite clear whether it is only useful to those transitioning from CVS/SVN or whether the facilities would also be useful to others.
Built on top of fast-export and fast-import, which I contend is the right architecture for a history filtering tool (see below).

I have read the reposurgeon documentation multiple times over the years, and am almost at a point where I feel like I know how to get started with it. I haven’t had a need to convert a CVS or SVN repo in over a decade; if I had such a need, perhaps I’d persevere and learn more about it. I suspect it has some good ideas I could apply to filter-repo. But I haven’t managed to get started with reposurgeon, so clearly my impressions of it should be taken with a grain of salt.

fast-export and fast-import

Finally, fast-export and fast-import can be used with a little editing of the fast-export output to handle a number of history rewriting cases. I have done this many times, but it has some drawbacks:

Dangerous for programmatic edits: It’s tempting to use sed or perl one-liners to e.g. try to modify filenames, but you risk accidentally also munging unrelated data such as commit messages, file contents, and branch and tag names.
Easy to miss corner cases: for example, fast-export only quotes filenames when necessary; as such, your attempt to rename a directory might leave files with spaces or UTF-8 characters in their original location.
Difficult to directly provide higher level facilities: for example, rewriting (possibly abbreviated) commit hashes in commit messages to refer to the new commit hashes, or stripping of non-merge commits which become empty or merge commits which become degenerate and empty.
Misses a lot of pieces needed to round things out into a usable tool.

However, fast-export and fast-import are the right architecture for building a repository filtering tool on top of; they are fast, provide access to almost all aspects of a repository in a very machine-parseable format, and will continue to gain features and capabilities over time (e.g. when replace refs were added, fast-export and fast-import immediately gained support). To create a full repository surgery tool, you “just” need to combine fast-export and fast-import together with a whole lot of parsing and glue, which, in a nutshell, is what filter-repo is.

Upstream improvements

But to circle back to the question of improving existing tools, during the development of filter-repo and its predecessor, lots of improvements to both fast-export and fast-import were submitted and included in git.git.

(Also, filter-repo started in early 2009 as git_fast_filter.py and therefore technically predates both BFG and reposurgeon.)

Why not a builtin command?

One could ask why this new command is not written in C like most of Git. While that would have several advantages, it doesn’t meet the necessary design requirements. See the “VERSATILITY” section of the manpage or see the “Versatility” section under the Design Rationale of the README.

Technically, we could perhaps provide a mechanism for people to write and compile plugins that a builtin command could load, but having users write filtering functions in C sounds suboptimal, and requiring gcc for filter-repo sounds more onerous than using python.

Where to from here?

This was just a quick intro to filter-repo, and I’ve provided a lot of links above if you want to learn more. Just a few more that might be of interest:

Ramifications of repository rewrites; including some tips (not specific to filter-repo)
Finding big objects/directories/extensions (and renames) in your repo (can be used together with tools other than filter-repo too)
Creating new history rewriting tools

Discussions

Reviews

[RFC/PATCH] CodingGuidelines: spell out post-C89 rules

Carlo Arenas recently commented on a patch by Emily Shaffer that moving a declaration out of a “for” loop would allow building on a CentOS 6 box.

Junio Hamano, the Git maintainer, replied to Carlo that we indeed “still reject variable definition in for loop control” even if “for past several years we’ve been experimenting with a bit more modern features”.

Junio then sent a patch to update the Documentation/CodingGuidelines file. This file describes which coding conventions are, and should be, used by developers working on the Git codebase.

One very important part of these conventions are the C language features that the developers are allowed or disallowed to use.

For a very long time, to be compatible with as many systems as possible, only features part of the C89 standard were allowed. Since 2012 though features part of the C99 standard have been very slowly introduced.

When these new features were introduced, they were introduced in “weather balloons” patches, which are very limited changes that are easy to undo in case someone complains.

Fortunately in most cases, though not in the “for” loop case, since the patches have been merged, no one has complained that they couldn’t compile Git’s code due to these patches, which means that code using these new features can now be more widely accepted.

The goal of Junio’s patch was to document that fact and these new features at the same time.

One of the new features is allowing an enum definition whose last element is followed by a comma. Jonathan Nieder replied to Junio that someone complained about that in 2010, but, as it has not happened since 2012 when the feature was reintroduced in the code base, it is ok.

Jonathan even suggested that we “say that the last element should always be followed by a comma, for ease of later patching”, and Junio found this idea interesting.

A few more comments were made by Jonathan and Bryan Turner about small possible improvements to Junio’s patch. Junio then sent an updated version of the patch which has since been merged to the master branch.

Developer Spotlight: Jean-Noël Avila

Who are you and what do you do?

My name is Jean-Noël Avila, father of three daughters and husband of an incredibly understanding wife. I graduated a long time ago from a french engineering school, with a speciality in signal processing, not really in computer science.

Professionally, I work in the R&D team of a small company that makes industrial online measurement systems, and guess what, we’re using Git as an ubiquitous revision control system (software, documentation); my colleagues know who they should call for any issue. Sadly though, I don’t work on Git.
What would you name your most important contribution to Git?

For the Git project itself, my most important and only contribution has been to deliver the french localization of the software since… 2013 (gasp!) and occasionally propose some patches to fix internationalization issues.

At the beginning, I proposed some patches to fix glob-pattern matching in the .gitignore file, but even if it fixed the issue, it turned out later that the patch had introduced a performance regression. So I chose to stick to a less harmful activity in the community (although bad translation can be quite harmful).

In the Git ecosystem more generally, I’ve been working on translating the Pro Git book to French and managing with Peff and Pedro (@pedrorijo91) the publishing of the translations of the book on http://git-scm.com. So, to sum it up, not working on the core, but on the public interfaces of the project.
What are you doing on the Git project these days, and why?

Following the path of localization, what is a localized application worth if the documentation is still an impediment? In this idea, at the beginning of this year, I’ve started an effort to translate the manual pages in French and to propose the translation framework put in place for this purpose to other languages.

So far, only two languages have translated content, but I expect to have some more soon. The pages are already available at http://git-scm.com/docs/. What is still missing is the packaging for other distributions of Git. Maybe when we have more content to provide.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Functionally, we’ve been bitten by some wrong merges of concurrent branches, and I wish Git could have some knowledge in patch algebra to better handle these corner cases. I know that it would be quite orthogonal to the present design, but even just detecting and showing warnings that something nasty is happening would prevent surprises (to say the least) of the users in complex histories.

From a translator’s stand point, a project that would not require a big expertise while still being useful would be to introduce rules and factorize internationalization. This part of Git is still the wild west by some aspects with a lot of freedom left to developers to choose their own formatting. A sizeable part of these strings are almost identical: with or without an ending period, with quoted or unquoted %s, with uppercase or not. Some strings are very similar: “foo and bar are mutually exclusive”, and so on. In the end, the number of segments to translate in Git amounts to 4674 for v2.23.0, which basically bars the entry to new translations.

As an aside, providing a po file for core strings and another one for less used strings would also help kickstart translations by focusing on more productive work for translators of new languages. I understand this kind of task would be Sisyphos’ work, but that would really help the community grow by giving access to Git to users less educated in computer science.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Translating Git and the manpages gives a good overview of what’s available and what is being introduced. So far, I haven’t experienced anything strikingly bad about a particular feature. At the limit, I would make rebasing require a more advanced knowledge of Git’s internals by not providing such an easy way to shoot in one’s foot.
What is your favorite Git-related tool/library, outside of Git itself?

In fact, in my daily work with Git, I don’t use the command line that much. I’m an Emacs fan, and Magit is really a miraculous tool when it comes to interacting with a Git repository from my favorite editor.

Releases

Git 2.23.0, 2.22.1, 2.23.0-rc2, 2.23.0-rc1, 2.23.0-rc0
Git for Windows 2.23.0
libgit2 0.28.3
libgit2sharp 0.26.1
Bitbucket Server 6.5
Gerrit Code Review 2.15.15, 2.16.11
GitHub Enterprise 2.17.6, 2.16.15, 2.15.20
GitLab 12.1.6, 12.1.4, 12.1.3, 12.1.2, 12.1.1
GitKraken 6.1.3, 6.1.2, 6.1.1, 6.1.0
GitHub Desktop 2.1.1

Other News

Various

The first translations of manpages are finally hitting git-scm.com. The project was kicked off and announced in January 2019. It was decided to hold the translation outside the main git repository and use a converter from the original asciidoc format to gettext po. After some more work on tooling and more people joining the project, the toolchain to allow publishing on git-scm.com is in place and you can already see some results. There are presently 9 languages of which 2 have several complete translated manpages. The upcoming tasks are to direct priority-oriented translators to most viewed content and generate packages for distribution along Git itself.
GitHub Actions now supports CI/CD, free for public repositories

Light reading

A Deep Dive into Git Performance using Trace2 by Jeff Hostetler explains everything about the Trace2 logging framework which was released in Git 2.22.0.
Documenting Proper Git Usage by Zack Brown in Linux Journal, mainly about the Rebasing and merging in kernel repositories article by Jonathan Corbet in LWN.net, mentioned in Git Rev News Edition #52.
Patch Workflow With Mutt - 2019 by Greg Kroah-Hartman.
Using Conventional Commit in Projects by Sathyabodh Mudhol on DZone. Conventional Commits specification was mentioned in Git Rev News Edition #52.

Git tools and sites

Game of Trees (Got) is a version control system developed by and for OpenBSD developers which prioritizes ease of use and simplicity over flexibility. Got wants to remain on-disk compatible with bare Git repositories.
git-revise by Nika Layzell is a history editing tool designed for the patch-stack workflow (similarly to StGit, Quilt, Guilt (formerly gq) or TopGit). It is intended to be fast, at least for small editing tasks; it is not meant to be a complete replacement for git rebase -i.
StoryTime is a tool that enables developers to easily simulate debugger-like visuals to tell or read a story about pieces of code (in their GitHub repositories).

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from Elijah Newren, Jeff Hostetler, Andrew Ardill and Jean-Noël Avila.

Git Rev News Edition 53 (July 24th, 2019)

chriscool — Wed, 24 Jul 2019 11:06:51 +0000

Git Rev News: Edition 53 (July 24th, 2019)

Welcome to the 53rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of June 2019.

Discussions

Reviews

Easy bulk commit creation in tests

Derrick Stolee, who prefers to be called Stolee, has been sending “Git Test Coverage Report” emails to the mailing list since September 2018.

These emails contain reports made using contrib/coverage-diff.sh to combine the gcov output from make coverage-test ; make coverage-report with the output from git diff A B to discover new lines of code that are not covered by the test suite.

In June 2019 Stolee sent a new report which stated that some new lines of code contributed by Jeff King, alias Peff, were not covered by any test. Peff replied that when running the test that exercises the surrounding code, we hit the early return above the lines that are not tested when there are fewer than 100 commits to index.

One solution to that problem could be to create 100 commits, instead of just 10, in the test, though that would slow down the test. Peff then concluded:

It would be nice if we had a “test_commits_bulk” that used fast-import to create larger numbers of commits.

A few hours later Peff replied to himself by sending a 6 patch long patch series which implements the test_commit_bulk function he suggested.

In this patch series Peff converted a few places in the code to use this function and reported that it saves around 7.5 seconds from his test runs. He commented: “Not ground-breaking, but I think it’s nice to have a solution where we don’t have to be afraid to generate a bunch of commits.”

The comments above the function explains it like this:
```
# Similar to test_commit, but efficiently create <nr> commits, each with a
# unique number $n (from 1 to <nr> by default) in the commit message.
#
# Usage: test_commit_bulk [options] <nr>
#   -C <dir>:
#	Run all git commands in directory <dir>
#   --ref=<n>:
#	ref on which to create commits (default: HEAD)
#   --start=<n>:
#	number commit messages from <n> (default: 1)
#   --message=<msg>:
#	use <msg> as the commit message (default: "commit $n")
#   --filename=<fn>:
#	modify <fn> in each commit (default: "$n.t")
#   --contents=<string>:
#	place <string> in each file (default: "content $n")
#   --id=<string>:
#	shorthand to use <string> and $n in message, filename, and contents
#
# The message, filename, and contents strings are evaluated by the shell inside
# double-quotes, with $n set to the current commit number. So you can do:
#
#   test_commit_bulk --filename=file --contents='modification $n'
#
# to have every commit touch the same file, but with unique content. Spaces are
# OK, but you must escape any metacharacters (like backslashes or
# double-quotes) you do not want expanded.
```
Johannes Schindelin replied to Peff that he likes the direction because “it would make it super easy to go one step further that would probably make a huge difference on Windows: to move test_commit_bulk to test-tool commit-bulk”.

Peff replied that “in the biggest case we dropped 900 processes to 4” so that he thought it would not make a big difference to convert test_commit_bulk to C code and integrate it as test-tool commit-bulk. But anyway Peff suggested 3 different ways to have only 1 process.

One of the ways Peff suggested was to add a feature to fast-import to say “build on top of ref X”. Elijah Newren replied to Peff that such a feature already exists using something like from refs/heads/branch^0.

Peff thanked Elijah and used the feature in a patch he attached, which further reduces the number of processes used.

Ævar Arnfjörð Bjarmason also replied to Peff wondering if just having a few “template” repositories, that could just be copied in many tests, would be a better approach.

Peff replied to Ævar that just “seeing the end result of running a bunch of commands” is less instructive than following “the steps that the author was thinking about”, and that “it’s more annoying to update”. Peff though would find cool that we could “allow caching of the on-disk state at certain points in a test script”, for example by annotating some test snippets as “SETUP”, like a prerequisite.

Stolee also replied to Peff, congratulating him for the quick turnaround, providing results from performance tests on Windows which were similar as those provided by Peff, and suggesting possible improvements to the test_commit_bulk function. These suggestions were then discussed by Junio Hamano, the Git maintainer, and Peff.

Junio, Ævar, Eric Sunshine and Gábor Szeder also discussed with Peff some aspects of the implementation and documentation of the new feature.

Peff then sent a version 2 of the patch that implements test_commit_bulk with many of the improvements that had been discussed. Junio discussed the implementation a bit further, but seemed happy with the patch series.

Peff recently sent a version 3, which will hopefully be merged soon.

Releases

GitLab 12.1.0, 12.0.3, 11.11.5, and 11.10.8, 12.0.2, 12.0.1, 12.0
Bitbucket Server 6.5
Gerrit Code Review 2.16.10, 3.0.1
GitHub Enterprise 2.17.5, 2.16.14, 2.15.19, 2.17.4, 2.16.13, 2.15.18, 2.14.25, 2.17.3, 2.16.12, 2.15.17, 2.14.24
GitHub Desktop 2.1.0
GitKraken 6.0.1

Other News

Various

Synergy is looking for a Git expert to join as a partner or in a freelance role. We are a startup developing an Enterprise Content Management solution for the office worker and we are looking to expand the team to build our GUI client and manage the infrastructure. If interested, please reach out to jaime.rivas@synergy.page

Light reading

My Personal Git Tricks Cheatsheet by Antonin Januska, with some improvements based on feedback in comments
Manage your dev.to blog posts from a Git repo and use continuous deployment to auto publish/update them by Maxime (@maxime1992)
Object Oriented Programming in C: A Case Study - Git and Linux Kernel: slides by Matheus Tavares and Renato Lui Geh (PDF)
C# or Java? TypeScript or JavaScript? Machine learning based classification of programming languages by Kavita Ganesan on GitHub Blog (OctoLingua project)

Git tools and sites

CallPath, by Matheus Tavares, “lets you see all the paths your code take until a specified function”. Matheus is a Google Summer of Code student currently working on making pack access code thread-safe.
diffr, by Nathan Moreau, is a new diff highlighting tool “trying to improve on the diff-highlight script distributed with Git”.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from Jaime Rivas and Carlo Marcelo Arenas Belón.

Git Rev News Edition 52 (June 28th, 2019)

chriscool — Fri, 28 Jun 2019 11:06:51 +0000

Git Rev News: Edition 52 (June 28th, 2019)

Welcome to the 52nd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of May 2019.

Discussions

General

I made a flame graph renderer for git’s trace2 output

Ævar Arnfjörð Bjarmason sent an email saying he developed a script that uses the FlameGraph tool to generate a picture showing where Git’s test suite spends its time.

His script also uses the new Git Trace2 API which has been developed mostly by Jeff Hostetler starting nearly one year ago and then through different versions: RFC, V1, V2, V3, V4, V5, and which has eventually been released in Git v2.22.0 at the beginning of June 2019.

Ævar added that he plans to improve his script over time and maybe submit it in a pull request to the FlameGraph tool, or perhaps integrate it in the Git test suite.

Derrick Stolee, who prefers to be called just Stolee, replied that he liked the idea and sent the commands using Ævar’s script that he used to create another picture from a much smaller test.

Gábor Szeder commented on Stolee’s commands to ask why GIT_TR2 instead of GIT_TRACE2 was used in the environment variables related to the Trace2 API. Gábor referred to Ken Thompson “who (allegedly?) later regretted spelling creat()/O_CREAT without the ‘e’…”.

Jeff King, alias Peff, replied to Ævar’s initial email asking “doesn’t perf record -g make test already give us that granular data?” referring to the Linux perf tool which is already supported by the FlameGraph tool. Peff also wondered about the usefulness of such a graph:

But having generated such a flamegraph, it’s not all that helpful. It mainly tells us that we spend a lot of time on fork/exec. Which is no surprise, since the test suite is geared not towards heavy workloads, but lots of tiny functionality tests.

Though he agreed that it could help in some cases:

I think the trace2 flamegraph would be most useful if you were collecting across a broad spectrum of workloads done by a user. You can do that with perf or similar tools, but it can be a bit awkward.

Ævar replied that his “actual use-case for this is to see what production nodes are spending their time on, similar to what Microsoft is doing with their use of this facility”, and that he used the test suite because it is a good way to test his script and the Trace2 API as “we’re pretty much guaranteed to run all our commands, and cover a lot of unusual cases”.

Ævar pointed that his work “shows that we’ve got a long way to go in improving the trace2 facility, i.e. adding region enter/leave for some of the things we spend the most time on.”

Jeff Hostetler, who authored the Trace2 API and works for Microsoft along with Stolee, then replied “Very Nice!” to Ævar and agreed with him about the work still needed “to get more granular data for interesting/problematic things”.

Ævar and Jeff then discussed this future work further in a few emails.

Jeff also replied to Gábor that he was ok to change TR2 to TRACE2, and Gábor sent two patches to get that change done. These patches were agreed on and merged before Git v2.22.0 was released on June 7th, 2019.

Reviews

[PATCH 00/17] [RFC] Commit-graph: Write incremental files

The road to incremental serialized commit-graph started with an attempt to create commit-graph file format v2
The commit-graph file format has some shortcomings that were discussed on-list:
1. It doesn’t use the 4-byte format ID from the_hash_algo.
2. There is no way to change the reachability index from generation numbers to corrected commit date.
3. The unused byte in the format could be used to signal the file is incremental, but current clients ignore the value even if it is non-zero.
This series adds a new version (2) to the commit-graph file. The fifth byte already specified the file format, so existing clients will gracefully respond to files with a different version number. The only real change now is that the header takes 12 bytes instead of 8, due to using the 4-byte format ID for the hash algorithm.
(Note that switching to corrected commit date as generation number v2 was covered in Git Rev News edition 45, November 2018).

It turned out however that the statement “existing clients will gracefully respond to files with a different version number” unfortunately turned out to be not true. Ævar Arnfjörð Bjarmason noticed that older Git responds with a hard error to commit-graph v2, instead of simply turning the serialized-graph feature off in such case.
[…] writing a v2 file would make most things (e.g. “status”) hard error on e.g. v2.21.0:
```
$ git status
error: graph version 2 does not match version 1
$
```
Now as noted in my series we now on ‘master’ downgrade that to a warning (along with the rest of the errors):
```
$ ~/g/git/git --exec-path=$PWD status
error: commit-graph version 2 does not match version 1
On branch master
[...]
```
…and this series sets the default version for all new graphs to v2.

I think this is way too aggressive of an upgrade path. If these patches go into v2.22.0 then git clients on all older versions that grok the commit graph (IIRC v2.18 and above) will have their git completely broken if they’re in a mixed-git-version environment.
The workaround is easy: removing .git/info/commit-graph, or using “git -c core.commitGraph=false ...”. However it is not possible to e.g. add advice describing the workaround to past Git versions (and new versions would simply not fail hard on v2).

It turned out that there is no need to introduce new commit-graph file format to achieve [almost] all stated goals. The goal 1.) turned out to be not important.
- Let’s just live with “1” as the marker for SHA-1.
  
  Yeah it would be cute to use 0x73686131 instead like “struct git_hash_algo”, but we can live with a 1=0x73686131 (“sha1”), 2=0x73323536 (“s256”) mapping somewhere. It’s not like we’re going to be running into the 255 limit of hash algorithms Git will support any time soon.
For 2.), Stolee noticed that generation number v2 (corrected commit date) can be made backward compatible

Since we can make the “corrected commit date” offset for a commit be strictly larger than the offset of a parent, we can make it so an old client will not give incorrect values when we use the new values. The only downside would be that we would fail on ‘git commit-graph verify’ since the offsets are not actually generation numbers in all cases.

This is discussed in a bit more detail in Re: Revision walking, commit dates, slop thread.

The issue of incremental commit-graph file, i.e. 3.), turned out to be better solved by keeping the base as backward-compatibile commit-graph, and deltas as separate files. Thus “Create commit-graph file format v2” turned into Commit-graph write refactor, and Stolee started a separate [RFC] Commit-graph: Write incremental files thread.

The original idea was to store subsequent deltas (incremental additions to serialized commit-graph data) in files named commit-graph-2, commit-graph-3, etc. After involved discussion, considering problems of concurrency, at V6 the design has changed, to having commit-graphs/graph-{hash}.graph together with commit-graph-chain index file.

The commit-graph is a valuable performance feature for repos with large commit histories, but suffers from the same problem as git repack: it rewrites the entire file every time. This can be slow when there are millions of commits, especially after we stopped reading from the commit-graph file during a write in 43d3561 (commit-graph write: don’t die if the existing graph is corrupt).

Instead, create a “chain” of commit-graphs in the .git/objects/info/commit-graphs folder with name graph-{hash}.graph. The list of hashes is given by the commit-graph-chain file, and also in a “base graph chunk” in the commit-graph format. As we read a chain, we can verify that the hashes match the trailing hash of each commit-graph we read along the way and each hash below a level is expected by that graph file.

When writing, we don’t always want to add a new level to the stack. This would eventually result in performance degradation, especially when searching for a commit (before we know its graph position). We decide to merge levels of the stack when the new commits we will write is less than half of the commits in the level above. This can be tweaked by the --size-multiple and --max-commits options.

This series, as ‘ds/commit-graph-incremental’ branch, is currently marked as ready to be merged into ‘next’.

Developer Spotlight: Jeff Hostetler

Who are you and what do you do?

My name is Jeff Hostetler and I work for Microsoft. I’ve been working on Git and on Git-related technologies for the last 5 years. Primarily focusing on performance and scale.

Prior to joining Microsoft, I worked for SourceGear and built the Veracity DVCS and the DiffMerge visual diff and merge tool.

A long, long time ago I was Architect for Spyglass Mosaic.
What would you name your most important contribution to Git?

I’d have to say the Trace2 facility that is now in v2.22. With this in place, it will be much easier to understand performance bottlenecks at scale.

Second to that would be the beginnings of the Partial Clone feature. There’s still a lot of work to do in this area, but I think long term, it will be central to solving certain enterprise-level scale problems.
What are you doing on the Git project these days, and why?

I’m currently working on a series of blog posts explaining Trace2 and how it can be used to measure and track Git performance.

Within Microsoft we continue to study Trace2 data generated by our Windows and Office developers and look for opportunities to improve the developer experience, such as making status and checkout faster. And we are using the data to guide how/where we should invest our engineering time for future performance gains.

Hopefully, I can encourage others to start using Trace2, gather their own data and look for opportunities where they can help improve Git.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Bring together the Partial Clone and Sparse Checkout features to scale to large repos. This includes completing the end-user experience, so that it just works and doesn’t require any wizardry.

There are several dimensions that have similar, but not identical needs.

For example, a moderately-sized work tree with a few large blobs might use Partial Clone with the blob-size filter and only demand-fetch large blobs when actually needed. This could be seen as an easier to use solution than LFS.

Alternatively, a repo with a gigantic tree might use Partial Clone with the sparse filter (to get “cones” of the work tree). That could be coordinated with the sparse-checkout file to populate just the desired parts of the work tree. For some users this would be simpler than using GVFS.

Let’s add new porcelain commands to create, grow, and shrink the sparse-checkout file and automatically update the index, so that the user doesn’t have to manually manipulate it.

Investigate a bulk pre-fetch command or hook, such as before a checkout, to reduce the overhead of individually demand-loading missing objects.

Finally, update Protocol V2 to include whatever verbs we need to make all of this work efficiently.

With this we could probably retire most if not all of GVFS and hopefully let our Windows and Office developers use core Git and not need a private fork.
If you could remove something from Git without worrying about backwards compatibility, what would it be?

I’d like to revisit the design of the index. Switch to a sparse and hierarchical format, for example. This is a large task and touches everything from the on-disk format to every index-related loop in the program.

Ben Peart and Derrick Stolee both touched upon this in earlier issues.
What is your favorite Git-related tool/library, outside of Git itself?

I’m mostly a terminal user, so I don’t use very many third-party tools. I do highly recommend GitGitGadget. I use it to run CI builds on all Windows, Mac, and Linux and to send patches to the mailing list.

Releases

Git 2.22.0, 2.22.0-rc3, 2.22.0-rc2
Git for Windows 2.22.0
libgit2 0.28.2
GitHub Enterprise 2.17.2, 2.16.11, 2.15.16, 2.14.23, 2.17.1, 2.16.10, 2.15.15, 2.14.22, 2.17.0, 2.16.9, 2.15.14, 2.14.21
GitLab 12.0.1, 12.0, 11.11.3, 11.11.2, 11.10.6, 11.11.1, 11.10.5, and 11.9.12, 11.11
Bitbucket Server 6.4
Gerrit Code Review 2.15.14, 2.16.9
GitKraken 6.0.0, 5.0.4, 5.0.3, 5.0.2, 5.0.1, 5.0.0
GitHub Desktop 2.0.4, 2.0.3, 2.0.2, 2.0.1, 2.0.0
Sourcetree 3.2.1, 3.2

Other News

Various

GitHub Maintainer Security Advisories are a way to privately report vulnerabilities to OSS projects on GitHub, currently in a public beta. Those are a part of a larger effort by GitHub to support security (especially targeting OSS projects). For more information about this effort see the following GitHub Help pages:
- About maintainer security advisories
- About security alerts for vulnerable dependencies
Introducing new ways to keep your code secure by Justin Hutchings on GitHub Blog.
Announcing GitHub Sponsors: a new way to contribute to open source by Devon Zuegel on GitHub Blog; see also TechCrunch article by Frederic Lardinois on the same subject.
Introducing GitHub Package Registry by Simina Pasat on GitHub Blog; GitHub Package Registry feature is currently in limited beta (you need to sign up for the beta).

Light reading

FreeBSD and Git (PDF) – slides from Ed Maste’s presentation at the FreeBSD Vendor Summit 2018.
Things I Learnt The Hard Way (in 30 Years of Software Development) by Julio Biason, including few thoughts about the use of version control and Git.
Rebasing and merging in kernel repositories [LWN.net] by Jonathan Corbet.
Enforcing Conventional Commits using Git hooks by Enda Phelan. Conventional Commits is a specification for adding human and machine readable meaning to commit messages. The presented solution was turned into the Sailr project.
Learn Git concepts, not commands by Nico Riedmann: An interactive Git tutorial for beginners meant to teach you how Git works, not just which commands to execute.
A Git Origin Story by Zack Brown (2018).

Git tools and sites

Sailr: a global Git hook for adhering to the Conventional Commit specification

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from Jeff Hostetler, David Pursehouse and Johannes Schindelin.

Git Rev News Edition 51 (May 22nd, 2019)

chriscool — Wed, 22 May 2019 11:06:51 +0000

Git Rev News: Edition 51 (May 22nd, 2019)

Welcome to the 51st edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of April 2019.

Discussions

General

GSoC students and mentors 2019

Two students are going to work on Git during this summer as part of the GSoC (Google Summer of Code):
- Matheus Tavares is going to work on making pack access code thread safe. He will be mentored by Olga Telezhnaia, a former Outreachy intern, and Christian Couder. Matheus has prepared a blog to report about his experience.
- Rohit Ashiwal will work on improving consistency of sequencer commands. He will be mentored by Thomas Gummerer, a former GSoC student, and Elijah Newren. Rohit has also prepared a blog to report about his experience.
It will be the 12th time that the Git project will mentor students as part of the GSoC. Rohit and Matheus will be the 28th and 29th students mentored since 2007 when Git started participating in the GSoC.

It will be the 15th year of GSoC and to celebrate that Google decided to have the GSoC Mentor Summit 2019 in a hotel in Munich, Germany instead of a Google campus in California. The Mentor Summit will last 3.5 days (Thursday, October 17 - Sunday, October 20) instead of the usual 2.5 days. The additional day, Friday, October 18, will be “Fun Day Activities for attendees to explore Munich and get to know each other before the unconference begins”.

Reviews

[RFC PATCH] *.h: remove extern from function declarations

Denton Liu sent a big RFC patch that removes extern keywords in front of function declarations and that affects ‘.h’ header files in large numbers.

He said that he used the following command to remove the keywords:
```
$ git ls-files '*.h' | xargs sed -i'' -e 's/^$\s*$extern $.*($/\1\2/'
```
And the following one to check the result:
```
$ git grep -w extern '*.h'
```
Jeff King, alias Peff, replied that dropping extern should not be done on function pointer declarations though, as a function pointer is a variable, so its visibility would change if extern is removed in front of it.

Junio agreed with Peff and explained that the reason we avoid wholesale updates “is because of an unnecessary bug like this one, not the one-time conflict resolution load that can be subcontracted out to ‘rerere’ once dealt with ;-)”.

Junio also suggested using “a tool more suited for the job (e.g. spatch)” as it “raises the confidence level of the end result a lot more than a ‘sed and then eyeball’ rewrite”, though we then have to be careful about possible “bugs in the instructions we give to the tool”.

Denton then sent a second version of his work. It was now a 3 patch long patch series.

The first patch used the spatch tool to do most of the extern keyword removals. The second patch still used sed to do it where spatch didn’t work, but it made sure to ignore function variables. The third patch used a Coccinelle script to make sure that no more extern keywords are added to the code base.

Thomas Gummerer replied to the first patch that it “leaves a bunch of oddly indented parameter lists behind”, as when a function has a larger number of parameters, its declaration often spans more than one line.

Denton then send a third version of his work, with an additional patch to “manually align parameter lists that were mangled by the tools”.

Peff replied wondering if it was a good thing to modify files in the compat/ directory as the code there is often “copied from elsewhere”. He also wondered if it was worth keeping the Coccinelle script as it is expensive to run.

In the fourth version of his work, Denton decided to keep the Coccinelle script, but excluded the compat/ directory from the files where extern is removed.

Junio noticed that in a commit message Denton mentioned using:
```
$ git ls-files \*.{c,h} | \
    grep -v ^compat/ | \
    xargs sed -i'' -e 's/^$\s*$extern $[^(]*([^*]$/\1\2/'
```
and then asked him to remove the useless backslashes at the end of the first 2 lines above, saying:

Your shell knows its own syntax sufficiently well, and when you end a line with a pipe, it knows that you haven’t finished speaking to it and waits for you to give the command downstream of the pipe, without being told that you haven’t finished with a backslash.

Unfortunately Gábor Szeder then found that the Coccinelle script failed on ‘compat/obstack.h’ as it is included in a ‘.c’ file checked by Coccinelle scripts.

Denton replied by proposing to drop the patch that contained his Coccinelle script, but Johannes Schindelin, alias Dscho, suggested to exclude certain directories or certain files for certain Coccinelle scripts.

There was then a long discussion thread involving Peff, Denton, Jacob Keller, Dscho, Junio and Gábor about what was possible to do with Coccinelle and spatch and how they are used in the Git toolchain. This thread eventually resulted in Peff writing a small series of patches, based on a previous patch by Jacob, that makes it possible to run Coccinelle faster on machines with a lot of memory. Peff’s patches have since been merged into the ‘master’ branch.

Denton in the meantime sent a fifth version of his work that drops the patch that contained his Coccinelle script, and loses the useless backslashes. This patch series has also been merged into the ‘master’ branch and will be part of Git v2.22.0 that should be released at the beginning of June 2019.

Developer Spotlight: Denton Liu

Who are you and what do you do?

My name is Denton and I’m a relatively new contributor to Git. I’m a Software Engineering student at the University of Waterloo and I’ve been bouncing around from internship to internship until I graduate next year.

I got started just over half a year ago when we had an assignment in school that required us to make a contribution to some open-source project. Since Git is so ubiquitous for developers, my team decided to target it.

Since then, I never really stopped because I’ve been having a lot of fun with it.
What would you name your most important contribution to Git?

I haven’t really been as prolific as other contributors so I wouldn’t say that my contributions are “important”, per se. I guess the most important contribution that I’ve made (although it’s still cooking) is teaching --keep-base to rebase.

Judging from the number of StackOverflow posts about it, I guess people expect this to be a feature but, since it’s not, I think most people alias it away or something.

Hopefully, this will be helpful to all the good people in the world who bother to clean up their branches before sending them up ;).
What are you doing on the Git project these days, and why?

I’d say that I’m a “selfish” contributor to Git. What I mean by this is I’ve only been working on features that I’ve wanted.

I keep a todo list on my phone of feature requests that I would like in Git and, whenever I have some free time, I’ll code it up. So these days, I’m mostly working all over the place, but mostly at a pretty high level.

Why? Because it’s fun :). It’s always cool running git pull upstream master and seeing your work in there.
If you could get a team of expert developers to work full time on something in Git for a full year, what would it be?

Hmm, it would be nice if Git’s interface were a little more standardised.

If I could get a team of developers working on Git, I’d probably get them to clean up Git’s user interface and make it more consistent with itself.

In this regard, Duy has been making me happy with his work making Git externally and internally consistent with git-restore, git-switch and the diff-parseopt changes but if we could have a team of Duys working, that would be amazing!
If you could remove something from Git without worrying about backwards compatibility, what would it be?

Continuing the above, my biggest gripe about Git is how inconsistent its interface is since it was developed organically. I think the biggest example of this would be how the meaning of .. and ... are essentially swapped in diff compared to the log family of commands. I always end up using the wrong number of dots because of this.

If I could change one thing about Git, it’d probably be the above. Even though it’s a very small thing, it trips me up a lot of the time.
What is your favorite Git-related tool/library, outside of Git itself?

I like to keep my setup as vanilla as possible so that when I move onto other machines, I don’t have to adjust my workflow very much so I only really use the stock Git. However, a while back, I was reading about git-imerge by Michael Haggerty.

I’m very thankful that I haven’t had to deal with any painfully large merges recently that have necessitated it but I’m keeping this tool in my back pocket in case the situation ever comes up.
Anything else you’d like to add?

I’d like to thank the more seasoned members of the Git project for being patient and helping me learn even through the (many) mistakes I’ve made through the process. In particular, in no particular order, I’d like to thank Junio, Ævar, Phillip Wood, Johannes Schindelin, Eric Sunshine and many others for helping me.

Releases

Git 2.22.0-rc1, 2.22.0-rc0
Git for Windows 2.22.0-rc1, 2.22.0-rc0
Gerrit Code Review 3.0.0
GitHub Enterprise 2.16.8, 2.15.13, 2.14.20, 2.16.7, 2.15.12, 2.14.19
GitLab 11.10.4, 11.10.3, 11.9.11, and 11.8.10, 11.10.2, 11.10.1
Bitbucket Server 6.3
GitHub Desktop 1.6.6
git-cinnabar 0.5.1

Other News

Various

Git and the new SHA-1 prefix collision attack is an email by Ævar Arnfjörð Bjarmason that has information and links about a newly published paper about new attacks building on the known “SHAttered” attack.
On April 1st, Ævar sent a two patches long patch series to the mailing list. These April fool’s day patches were “praise: a culturally sensitive wrapper for ‘blame’” and “praise: make ‘blameless’ cultural enforcement configurable”.
Dave Borowitz, one of the top contributors of Gerrit Code Review, leaves the project after 9k reviews, 3.4k commits and 8 years of contributions.
Someone Is Hacking GitHub Repositories and Holding Code Ransom, which lead to Git ransom campaign incident report—Atlassian Bitbucket, GitHub, GitLab; this topic was also discussed on git mailing list: Git ransom campaign incident report - May 2019.

Light reading

Exploring new frontiers for Git push performance includes a description of the new “sparse” push algorithm, enabled by the pack.useSparse config option.
The Developer Homepage of Derrick Stolee contains a number of interesting articles, presentations and links especially about features he developed like the commit-graph.
The history behind 6 years of development of Gerrit v3.0 goes back in time and describes the long path from the original greenish GWT UI until the latest shiny blue Polymer-based user experience.
git rebase in depth, a guide to help demystify the powerful git-rebase.
Signing Git Commits by Kyle Rankin, from Linux Journal.
Git does not remember username and password on Windows by André Snede Kock, or how to use Windows Credentials manager with Git, and how to manually set credentials if needed.
Stupid git tricks: Combining two files into one while preserving line history by Raymond Chen; the trick is to create a rename/rename merge commit.
The Essential Git Handbook by Sanjula Madurapperuma, teaching a little about Git.
Squash commits when merging a Git branch with Bitbucket by Abhin Chhabra.
Serving Vue.js apps on Github Pages by Muhammad Usman; the trick is to configure GitHub Pages and use ‘docs’ folder.

Git tools and sites

gitfolio: personal website + blog for every GitHub user (JavaScript with Node.js); see https://imfunniee.github.io/gitfolio/.
GitHub Learning Lab: learn new skills by completing fun, realistic projects in your very own GitHub repository.
fh: record changes to a file on a per-file basis, with ed(1), diff(1), awk(1), sed(1) and sh(1).
commit-messages-guide: a guide to understand the importance of commit messages and how to write them well.

Credits

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Gabriel Alcaras <gabriel.alcaras@telecom-paristech.fr> with help from David Pursehouse, Luca Milanesio and Denton Liu.