anchor.diff:  , libcap
   , libopus
   , libsndfile
  +, mesa_noglu
   , qt4
   , qt5
  +, openssl
   , protobuf
   , speex
  +, xorg
   
   , iceSupport ? true, zeroc_ice
   , jackSupport ? false, jack2_lib
  
positive.code:       qt5.qtbase
      ];
  
      buildInputs = [
        avahi
        boost
        protobuf
      ] ++ optionals (source.qtVersion == 4) [
        qt4
  
negative.code:       alsa-lib
        libopus
        libsndfile
        mesa_noglu
        speex
        xorg.inputproto
        xorg.libX11
        xorg.libXext
        xorg.libXfixes
        xorg.libXi
      ] ++ optionals (source.qtVersion == 5) [
        qt5.qtsvg
      ] ++ optionals jackSupport [
  