anchor.diff:          exit 2
       fi
   
  -    darwinPath=$(NIX_PATH=${concatStringsSep ":" config.nix.nixPath} nix-instantiate --eval -E '<darwin>') || true
  +    darwinPath=$(NIX_PATH="${concatStringsSep ":" config.nix.nixPath}${optionalString config.nix.enableChannels ":$HOME/.nix-defexpr/channels:/nix/var/nix/profiles/per-user/root/channels"}" nix-instantiate --eval -E '<darwin>') || true
       if ! test -e "$darwinPath"; then
           echo "[1;31merror: Changed <darwin> but target does not exist, aborting activation[0m" >&2
           echo "Add the darwin repo as a channel or set nix.nixPath:" >&2
  
positive.code:   '';
  
    nixPath = ''
      darwinConfig=$(NIX_PATH=${concatStringsSep ":" config.nix.nixPath} nix-instantiate --eval -E '<darwin-config>' || echo "$HOME/.nixpkgs/darwin-configuration.nix") || true
      if ! test -e "$darwinConfig"; then
          echo "[1;31merror: Changed <darwin-config> but target does not exist, aborting activation[0m" >&2
          echo "Create $darwinConfig or set environment.darwinConfig:" >&2
  
negative.code:         exit 2
      fi
  
      nixpkgsPath=$(NIX_PATH="${concatStringsSep ":" config.nix.nixPath}${optionalString config.nix.enableChannels ":$HOME/.nix-defexpr/channels:/nix/var/nix/profiles/per-user/root/channels"}" nix-instantiate --eval -E '<nixpkgs>') || true
      if ! test -e "$nixpkgsPath"; then
          echo "[1;31merror: Changed <nixpkgs> but target does not exist, aborting activation[0m" >&2
          echo "Add a nixpkgs channel or set nix.nixPath:" >&2
  