macOS: Paths cannot be opened from the Preferences window

Steps to reproduce:

1. Launch Inkscape
2. Open Inkscape > Edit > Preferences…
3. Select System
4. Click on one of the buttons labeled Open on the right hand side of any path

What happened?

Nothing

What should have happened?

The path location should have opened in Finder.

• Inkscape Version: 1.0alpha2 (e7074507, 2019-08-17)
• Operating System version: macOS Mojave 10.14.6 (18G87)