anchor.diff:      "--${boolEn (libdvdnav != null)}-dvdnav"
       # FIXME
       #"--${boolEn (libcdio != null)}-cdda"
  -    "--${boolEn (enca != null)}-enca"
       #"--${boolEn ( != null)}-uchardet"
       "--${boolEn (rubberband != null)}-rubberband"
       "--${boolEn (lcms2 != null)}-lcms2"
  
positive.code: 
    buildInputs = [
      alsa-lib
      enca
      ffmpeg
      freefont_ttf
      freetype
  
negative.code: , which
  
  , alsa-lib
  , ffmpeg
  , freefont_ttf
  , freetype
  