Troubleshooting

Apple upgrades

When upgrading macOS your /etc/zshrc might reset. Result: commands or configurations stop working, NIX_PATH is empty etc. Fix: Add this to the bottom of /etc/zshrc.

if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
. '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
fi

Touch ID for sudo

Enable sudo touch id auth

Also, macOS resets /etc/pam.d/sudo which enables touch id for sudo. More info here:

Node not available

If node isn't available check that host configuration has nix-ld enabled.

...
nixosConfigurations.host = nixpkgs.lib.nixosSystem {
  modules = [
    ./<host>/configuration.nix
    nix-ld.nixosModules.nix-ld
  ];
...

programs.nix-ld.dev.enable = true;