anchor.diff:      "--${boolWt (jasper != null)}-jasper"
       "--without-graphviz"
       "--without-lua"
  -    "--${boolWt (ffmpeg_3-4 != null)}-libavformat"
  +    "--${boolWt (ffmpeg != null)}-libavformat"
       "--${boolWt (v4l_lib != null)}-libv4l"
       "--${boolWt (lcms2 != null)}-lcms"
       "--${boolWt (libspiro != null)}-libspiro"
  
positive.code:     platforms;
  
    channel = "0.4";
    version = "${channel}.2";
  in
  stdenv.mkDerivation rec {
    name = "gegl-${version}";
  
    src = fetchurl {
      url = "https://download.gimp.org/pub/gegl/${channel}/${name}.tar.bz2";
      multihash = "QmTN1J6X7sjQ92JBQZptukofZGu6nZvjNKoqhRqndTudVc";
      hashOutput = false;
      sha256 = "6a358bc19d20b8ac1daf645cc8b53cdc2ea6f9c98a6036179a57045a26a07f8d";
    };
  
    nativeBuildInputs = [
  
negative.code: , babl
  , cairo
  , exiv2
  , ffmpeg
  , gdk-pixbuf
  , gexiv2
  , glib
  