anchor.diff:        environment.pathsToLink = [
           "/share/nautilus-python/extensions"
         ];
  -    })
  -
  -    # Enable default program modules
  -    # Since some of these have a corresponding package, we only
  -    # enable that program module if the package hasn't been excluded
  -    # through `environment.gnome3.excludePackages`
  -    (
  -    let
  -      notExcluded = pkg: mkDefault (!(lib.elem pkg config.environment.gnome3.excludePackages));
  -    in
  -    with pkgs.gnome3;
  -    {
  -      programs.evince.enable = notExcluded evince;
  -      programs.file-roller.enable = notExcluded file-roller;
  -      programs.geary.enable = notExcluded geary;
  -      programs.gnome-disks.enable = notExcluded gnome-disk-utility;
  -      programs.gnome-terminal.enable = notExcluded gnome-terminal;
  -      programs.seahorse.enable = notExcluded seahorse;
  -      services.gnome3.sushi.enable = notExcluded sushi;
       })
   
       (mkIf serviceCfg.games.enable {
  
positive.code:         /* gnome-boxes */
        ] config.environment.gnome3.excludePackages);
  
        # Let nautilus find extensions
        # TODO: Create nautilus-with-extensions package
        environment.sessionVariables.NAUTILUS_EXTENSION_DIR = "${config.system.path}/lib/nautilus/extensions-3.0";
  
negative.code:     '';
  
    flashbackEnabled = cfg.flashback.enableMetacity || length cfg.flashback.customSessions > 0;
  
    notExcluded = pkg: mkDefault (!(lib.elem pkg config.environment.gnome3.excludePackages));
  
  in
  
  