anchor.diff:      libspiro
       libtiff
       libwebp
  -    openexr
  +    #openexr 2.3.0 is broken for gegl 0.4.8
       pango
       v4l_lib
     ];
  
positive.code:     platforms;
  
    channel = "0.4";
    version = "${channel}.6";
  in
  stdenv.mkDerivation rec {
    name = "gegl-${version}";
  
    src = fetchurl {
      url = "https://download.gimp.org/pub/gegl/${channel}/${name}.tar.bz2";
      multihash = "QmPSjiRoCAUwrf42mUrjKDEXuy15a39xjy4z3zgbJA418e";
      hashOutput = false;
      sha256 = "f8cb45da736131fe29582b74cf6851102ae013bf99c77413a8bcb02e92e57890";
    };
  
    nativeBuildInputs = [
  
negative.code:     "--without-sdl"
      "--${boolWt (libraw != null)}-libraw"
      "--${boolWt (jasper != null)}-jasper"
      "--${boolWt (graphviz != null)}-graphviz"
      "--without-lua"
      "--${boolWt (ffmpeg != null)}-libavformat"
      "--${boolWt (v4l_lib != null)}-libv4l"
  