anchor.diff:      "--enable-volume"
       "--${boolEn (iso-codes != null)}-iso-codes"
       "--${boolEn (zlib != null)}-zlib"
  -    "--${boolEn (xorg.libX11 != null)}-x"
  +    "--${boolEn (libx11 != null)}-x"
       "--${boolEn (xorg.libXv != null)}-xvideo"
  -    "--${boolEn (xorg.libXext != null)}-xshm"
  +    "--${boolEn (libxext != null)}-xshm"
       "--${boolEn (alsa-lib != null)}-alsa"
       "--${boolEn (cdparanoia != null)}-cdparanoia"
       "--disable-ivorbis"
  
positive.code:     libtheora
      libvisual
      libvorbis
      opus
      orc
      pango
      xorg.libX11
      xorg.libXext
      xorg.libXv
      xorg.videoproto
      xorg.xextproto
      xorg.xproto
      zlib
    ];
  
  
negative.code: , libtheora
  , libvisual
  , libvorbis
  , libx11
  , libxext
  #, libxv
  , opus
  , orc
  , pango
  , videoproto
  , xextproto
  , xorg
  , xproto
  , zlib
  
  , channel
  