anchor.diff:      speech-dispatcher
       speex
       speexdsp
  -    xproto
  +    xorgproto
     ] ++ optionals (config == "murmur") [
       grpc
       ice
  
positive.code: , speech-dispatcher
  , speex
  , speexdsp
  , xproto
  
  , mumbleOverlay ? true
  , releaseType ? "release"
  
negative.code:     qt5
    ] ++ optionals (config == "mumble") [
      alsa-lib
      libsndfile
      libx11
      libxext
  