anchor.diff:  , curl
   , dconf
   , libepoxy
  -, ffmpeg
   , fftw
   , fftwFloat
   , flex
  
positive.code:   ];
  
    mesonFlags = [
      "-Denable_ffmpeg=true"
      "-Denable_rtmidi=true"
      "-Denable_rtaudio=true"
      "-Denable_sdl=true"
      "-Dcarla=enabled"
      "-Dmanpage=true"
      # "-Duser_manual=true" # needs sphinx-intl
  
negative.code:     curl
      dconf
      libepoxy
      fftw
      fftwFloat
      flex
  