Unfortunately, macOS always overwrites the /etc/zshrc file during updates. This is a problem insofar as the hook for Nix is here (and has to be here). To circumvent this problem, you can use a launchd job to check on every system start whether this hook still exists and rewrite it if necessary:
- create the file
/Library/LaunchDaemons/org.nixos.darwin.check-zshrc-nix-hook.plistwith the content mentioned below - set the correct user and access rights:
sudo chown root:wheel /Library/LaunchDaemons/org.nixos.darwin.check-zshrc-nix-hook.plist
sudo chmod u=rw,go=r /Library/LaunchDaemons/org.nixos.darwin.check-zshrc-nix-hook.plist