anchor.diff:  , samplerateSupport ? true, libsamplerate
   , mmsSupport ? true, libmms
   , mpg123Support ? true, mpg123
  -, aacSupport ? true, faad2 }:
  +, aacSupport ? true, faad2
  +, pulseaudioSupport ? true, pulseaudio
  +}:
   
   let
   
  
positive.code:       (mkFlag mmsSupport "mms")
        (mkFlag mpg123Support "mpg123")
        (mkFlag aacSupport "aac")
        (mkFlag stdenv.isDarwin "osx")
        "--enable-debugging" ]
      ++ opt stdenv.isLinux
  
negative.code:     ++ opt mmsSupport libmms
      ++ opt mpg123Support mpg123
      ++ opt aacSupport faad2
      ++ opt zipSupport zziplib
      ++ opt zipSupport pulseaudio;
  
    configureFlags =
      [ (mkFlag (!stdenv.isDarwin && alsaSupport) "alsa")
  