anchor.diff:      environment.pathsToLink =
         [ "/share/xfce4" "/share/themes" "/share/mime" "/share/desktop-directories" ];
   
  -    environment.shellInit = optionalString isXfce48
  +    environment.shellInit =
         ''
           export GIO_EXTRA_MODULES=${pkgs.xfce.gvfs}/lib/gio/modules
         '';
   
       # Enable helpful DBus services.
  -    services.hal = mkIf (!isXfce48) { enable = true; };
  -    services.udisks = mkIf isXfce48 { enable = true; };
  -    services.upower = mkIf (isXfce48 && config.powerManagement.enable) { enable = true; };
  +    services.udisks.enable = true;
  +    services.upower.enable = config.powerManagement.enable;
   
     };
   
  
positive.code:         # "utilities-terminal" and "accessories-text-editor".
          pkgs.gnome.gnomeicontheme
          pkgs.desktop_file_utils
        ]
        ++ optionals isXfce48 [
          pkgs.xfce.libxfce4ui
          pkgs.xfce.garcon
          pkgs.xfce.thunar_volman
  
negative.code:       };
  
      environment.systemPackages =
        [ pkgs.gtk # To get GTK+'s themes.
          pkgs.hicolor_icon_theme
          pkgs.shared_mime_info
          pkgs.which # Needed by the xfce's xinitrc script.
  