anchor.diff:        (filterAttrs (k: v: v != null) cfg.shellAliases)
     );
   
  +  envShellInit = pkgs.writeText "shellInit" cfge.shellInit;
  +
  +  envLoginShellInit = pkgs.writeText "loginShellInit" cfge.loginShellInit;
  +
  +  envInteractiveShellInit = pkgs.writeText "interactiveShellInit" cfge.interactiveShellInit;
  +
  +  sourceEnv = file:
  +  if cfg.useBabelfish then
  +    "source /etc/fish/${file}.fish"
  +  else
  +    ''
  +      set fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish-foreign-env/functions $fish_function_path
  +      fenv source /etc/fish/foreign-env/${file} > /dev/null
  +      set -e fish_function_path[1]
  +    '';
  +
  +  babelfishTranslate = path: name:
  +    pkgs.runCommand "${name}.fish" {
  +      nativeBuildInputs = [ pkgs.babelfish ];
  +    } "${pkgs.babelfish}/bin/babelfish < ${path} > $out;";
  +
   in
   
   {
  
positive.code:     # Required for man completions
      documentation.man.generateCaches = lib.mkDefault true;
  
      environment.etc."fish/foreign-env/shellInit".text = cfge.shellInit;
      environment.etc."fish/foreign-env/loginShellInit".text = cfge.loginShellInit;
      environment.etc."fish/foreign-env/interactiveShellInit".text = cfge.interactiveShellInit;
  
      environment.etc."fish/nixos-env-preinit.fish".text = ''
        # This happens before $__fish_datadir/config.fish sets fish_function_path, so it is currently
        # unset. We set it and then completely erase it, leaving its configuration to $__fish_datadir/config.fish
        set fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish/vendor_functions.d $__fish_datadir/functions
  
        # source the NixOS environment config
        if [ -z "$__NIXOS_SET_ENVIRONMENT_DONE" ]
            fenv source ${config.system.build.setEnvironment}
        end
  
        # clear fish_function_path so that it will be correctly set when we return to $__fish_datadir/config.fish
        set -e fish_function_path
      '';
  
      environment.etc."fish/config.fish".text = ''
        # /etc/fish/config.fish: DO NOT EDIT -- this file has been generated automatically.
  
        # if we haven't sourced the general config, do it
        if not set -q __fish_nixos_general_config_sourced
          set --prepend fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish/vendor_functions.d
          fenv source /etc/fish/foreign-env/shellInit > /dev/null
          set -e fish_function_path[1]
  
          ${cfg.shellInit}
  
          # and leave a note so we don't source this config section again from
          # this very shell (children will source the general config anew)
          set -g __fish_nixos_general_config_sourced 1
        end
  
        # if we haven't sourced the login config, do it
        status --is-login; and not set -q __fish_nixos_login_config_sourced
        and begin
          set --prepend fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish/vendor_functions.d
          fenv source /etc/fish/foreign-env/loginShellInit > /dev/null
          set -e fish_function_path[1]
  
          ${cfg.loginShellInit}
  
          # and leave a note so we don't source this config section again from
          # this very shell (children will source the general config anew)
          set -g __fish_nixos_login_config_sourced 1
        end
  
        # if we haven't sourced the interactive config, do it
        status --is-interactive; and not set -q __fish_nixos_interactive_config_sourced
        and begin
          ${fishAliases}
  
          set --prepend fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish/vendor_functions.d
          fenv source /etc/fish/foreign-env/interactiveShellInit > /dev/null
          set -e fish_function_path[1]
  
          ${cfg.promptInit}
          ${cfg.interactiveShellInit}
  
          # and leave a note so we don't source this config section again from
          # this very shell (children will source the general config anew,
          # allowing configuration changes in, e.g, aliases, to propagate)
          set -g __fish_nixos_interactive_config_sourced 1
        end
      '';
  
      programs.fish.interactiveShellInit = ''
        # add completions generated by NixOS to $fish_complete_path
  
negative.code:         type = types.bool;
        };
  
        useBabelfish = mkOption {
          type = types.bool;
          default = false;
          description = ''
            If enabled, the configured environment will be translated to native fish using <link xlink:href="https://github.com/bouk/babelfish">babelfish</link>.
            Otherwise, <link xlink:href="https://github.com/oh-my-fish/plugin-foreign-env">foreign-env</link> will be used.
          '';
        };
  
        vendor.config.enable = mkOption {
          type = types.bool;
          default = true;
  