anchor.diff:  , withMusicbrainz ? false, libmusicbrainz5
   
   , withTaglib ? true, taglib, taglib_extras
  +, withHttpStream ? true, qtmultimedia
   , withReplaygain ? true, ffmpeg, speex, mpg123
   , withMtp ? true, libmtp
   , withOnlineServices ? true
   , withDevices ? true, udisks2
   , withDynamic ? true
   , withHttpServer ? true
  +, withLibVlc ? false, vlc
   , withStreams ? true
   }:
   
  
positive.code:     (fstat withDynamic        "DYNAMIC")
      (fstat withDevices        "DEVICES_SUPPORT")
      (fstat withHttpServer     "HTTP_SERVER")
      (fstat withStreams        "STREAMS")
      (fstat withUdisks         "UDISKS2")
      "-DENABLE_HTTPS_SUPPORT=ON"
  
negative.code: assert withMusicbrainz -> withCdda && withTaglib;
  assert withOnlineServices -> withTaglib;
  assert withReplaygain -> withTaglib;
  assert withLibVlc -> withHttpStream;
  
  let
    version = "2.4.1";
  