anchor.diff:  , callPackage
   , nixosTests
   , withMediaSession ? true
  +, libcameraSupport ? true
  +, libcamera
  +, libdrm
   , gstreamerSupport ? true
   , gst_all_1 ? null
   , ffmpegSupport ? true
  
positive.code:       SDL2
        systemd
      ] ++ lib.optionals gstreamerSupport [ gst_all_1.gst-plugins-base gst_all_1.gstreamer ]
      ++ lib.optional ffmpegSupport ffmpeg
      ++ lib.optionals bluezSupport [ bluez libfreeaptx ldacbt sbc fdk_aac ]
      ++ lib.optional pulseTunnelSupport libpulseaudio
  
negative.code:       "-Dpipewire_pulse_prefix=${placeholder "pulse"}"
        "-Dmedia-session-prefix=${placeholder "mediaSession"}"
        "-Dlibjack-path=${placeholder "jack"}/lib"
        "-Dlibcamera=${mesonEnable libcameraSupport}"
        "-Droc=disabled"
        "-Dlibpulse=${mesonEnable pulseTunnelSupport}"
        "-Davahi=${mesonEnable zeroconfSupport}"
  