Describe the bug

The instructions at this issue comment to uninstall Nix do not work.

Steps To Reproduce

$ sudo rm -rf /nix
rm: /nix/.Spotlight-V100: Operation not permitted
rm: /nix/.Trashes: Operation not permitted
rm: /nix: Resource busy

Expected behavior

The directory should have been deleted. Apparently, some additional step is required. As suggested later in the linked issue thread, I already tried mounting, unmounting, rebooting, but to no avail.

nix-env --version output

Not available since I am trying to uninstall and already deleted the binaries.

Additional context

macOS Catalina, 10.15.6