NET SDK

#beginners #cli #dotnet #tutorial

Hey! Hope you're doing well.

So, I finally got around to setting up the .NET SDK on my Mac—you know, the official toolchain for building .NET apps cross-platform. I've been wanting to play with ASP.NET Core for a backend project, and the promise of writing C# on macOS sounded great.

Install was smooth—downloaded the installer from the official site, ran it, everything seemed fine. Opened Terminal, typed dotnet --version to verify… and got zsh: command not found. The SDK was installed, but the dotnet command wasn't in my PATH.

The Wrong Turn I Took First

My first thought: "Maybe the installer didn't add it to PATH." I checked /usr/local/share/dotnet/—the dotnet binary was there. So I manually added export PATH=$PATH:/usr/local/share/dotnet to my .zshrc, sourced it, and dotnet --version worked. Great, problem solved… or so I thought.

Then I tried creating a new project with dotnet new console. It created the project, but when I ran dotnet run, I got a cryptic error about being unable to load shared library. Something about permissions.

The "Aha!" Moment

I spent an hour chasing that error, reinstalling, checking dependencies. Then I realized: even though dotnet was in my PATH, the runtime needed to write temporary files and access certificates, and macOS was blocking it. The fix was two-fold:

Grant terminal app access in System Settings > Privacy & Security > Files and Folders. I enabled access for my terminal (iTerm2) to "Documents" and "Downloads"—that resolved the temp file issues.
Install the .NET certificates for HTTPS development. The SDK includes a tool for this: run dotnet dev-certs https --trust and enter your password when prompted. This adds the development certificate to your keychain.

After those two steps, dotnet run worked perfectly—"Hello, World!" printed instantly.

I found this page with the system requirements that mentioned the certificate step in the user comments: the resource I used. Super helpful for getting unstuck.