anchor.diff:      jobs.virtualbox =
         { description = "VirtualBox service";
   
  -        startOn = "started udev";
  +        wantedBy = [ "multi-user.target" ];
  +        requires = [ "dev-vboxguest.device" ];
  +        after = [ "dev-vboxguest.device" ];
   
           exec = "${kernel.virtualboxGuestAdditions}/sbin/VBoxService --foreground";
         };
  
positive.code:         # /dev/vboxuser is necessary for VBoxClient to work.  Maybe we
          # should restrict this to logged-in users.
          KERNEL=="vboxuser",  OWNER="root", GROUP="root", MODE="0666"
        '';
  
      # Make the ACPI Shutdown command to do the right thing.    
      services.acpid.enable = true;
      services.acpid.powerEventCommands = "poweroff";
    };
  
negative.code:       ''
          InputDevice "VBoxMouse"
        '';
  
      services.xserver.displayManager.sessionCommands =
        ''
          PATH=${makeSearchPath "bin" [ pkgs.gnugrep pkgs.which pkgs.xorg.xorgserver ]}:$PATH \
  