anchor.diff:  { stdenv
  +, fetchpatch
   , fetchurl
  +, lib
   , scons
   
   , chromaprint
   , faad2
  -, ffmpeg_2
  +, ffmpeg
   , fftw_double
   , flac
   , libid3tag
  
positive.code:   buildInputs = [
      chromaprint
      faad2
      ffmpeg_2
      fftw_double
      flac
      libid3tag
  
negative.code:     "verbose=0"
      "profiling=0"
      "test=0"
      "shoutcast=${bool01 (libshout != null)}"
      "opus=${bool01 (opus != null)}"
      "ffmpeg=${bool01 (ffmpeg != null)}"
      "optimize=portable"
      "autodjcrates=1"
      "macappstore=0"
  