anchor.diff:  , rtmpdump ? null, rtmpSupport ? true
   , libvdpau ? null, vdpauSupport ? true
   , libpulseaudio ? null, pulseSupport ? true
  -, libcec ? null, cecSupport ? true
   }:
   
   assert dbusSupport  -> dbus_libs != null;
  
positive.code: , lzo, libcdio, libmodplug, libass, libbluray
  , sqlite, mysql, nasm, gnutls, libva, wayland
  , curl, bzip2, zip, unzip, glxinfo, xdpyinfo
  , dbus_libs ? null, dbusSupport ? true
  , udev, udevSupport ? true
  , libusb ? null, usbSupport ? false
  
negative.code:       lzo libcdio libmodplug libass libbluray
        sqlite mysql.lib nasm avahi libdvdcss lame
        curl bzip2 zip unzip glxinfo xdpyinfo
        libcec libcec_platform
      ]
      ++ lib.optional dbusSupport dbus_libs
      ++ lib.optional udevSupport udev
  