Git fails to run: Failed to start Git process: cannot start program

Problem

The Settings > Version Control > Git dialogue outputs the following error message when it uses Git from the path, or when the path of Git is manually entered, for either Homebrew's git (in Mac OS) or the git installed by Nix Home Manager:

Failed to start Git process: Cannot run program "/opt/homebrew/Cellar/git/2.50.1/bin/git" (in directory "."): error=0, Failed to exec spawn helper: pid: 55321, exit value: 1

Resolution

Reboot the PC. After a reboot the git installed with Nix works without issue in both IntelliJ IDEA and PyCharm.