There is not an official tool yet (though I’m not sure an uninstall is necessary, in your case?)
This is very frequently requested. I’ve laid out roughly what I think it would take to be able to add an --uninstall flag to the installer in Anyone up for picking at some Nix ~onboarding improvements? and Installer test suite? :) small project(s), high-leverage, help wanted but I am not aware of anyone currently working on any of them.
IIRC the reboot step is just for macOS to clean up the empty root /nix directory (some people get confused when they follow uninstall steps and still see the /nix directory, then throw a fit about the uninstall steps not working). I’ll give more detail than you probably need in case others land here via search:
- There’s no way around needing to reboot to have macOS remove the directory that I am aware of. It isn’t friendly, but it’s a system limitation we have to live with (unless/until Apple add some way for us to imperatively clean it up).
- You can skip the reboot step if you understand the consequences. If you:
- do not plan to reinstall, you understand that you’ll have a /nix directory hanging around until your next reboot.
- plan to then install Nix 2.3.x: go ahead and reboot. IIRC the 2.3.x installer will be confused by the presence of the /nix directory and the install will fail.
- plan to then install Nix 2.4.x (prerelease or release): you shouldn’t need to reboot. This installer should not be confused by the dangling directory.