MacOS update and nix


I have seen whenever I update my mac m1, nix tools are no longer available in PATH. I think .zhrc gets modified with update. I noticed recently when I updated to macOS 12.0

How can I restore it.

This is a known issue, and there is a workaround given in this thread: macOS updates often break nix installation (updates replace path-hooks on multi-user install) · Issue #3616 · NixOS/nix · GitHub