anchor.diff:        '';
       };
   
  -    enableExtensionPack = mkEnableOption "VirtualBox extension pack";
  +    package = mkOption {
  +      type = types.package;
  +      default = pkgs.virtualbox;
  +      defaultText = "pkgs.virtualbox";
  +      description = ''
  +        Which VirtualBox package to use.
  +      '';
  +    };
   
       addNetworkInterface = mkOption {
         type = types.bool;
  
positive.code:         Automatically set up a vboxnet0 host-only network interface.
        '';
      };
  
      enableHardening = mkOption {
        type = types.bool;
  
negative.code: let
    cfg = config.virtualisation.virtualbox.host;
  
    virtualbox = cfg.package.override {
      inherit (cfg) enableExtensionPack enableHardening headless;
    };
  
  