anchor.diff:      elem
       platforms;
   
  -  channel = "0.3";
  -  version = "${channel}.34";
  +  channel = "0.4";
  +  version = "${channel}.0";
   in
   stdenv.mkDerivation rec {
     name = "gegl-${version}";
   
     src = fetchurl {
       url = "https://download.gimp.org/pub/gegl/${channel}/${name}.tar.bz2";
  -    multihash = "QmXDKVdYca9nWTKUXDkFm4J1B1nPVKQ7MTG4uKHSdmgDqN";
  +    multihash = "QmZiH6hCsnFLSyptFfGPQEFpzRheQ7AjEpy2mduLbig4Ns";
       hashOutput = false;
  -    sha256 = "5ca2227655ebf1ab2e252cee3eede219c758336394288ef301b93264b9411304";
  +    sha256 = "d04d2bfa0ff5a4bcfe7566f7418929a9c80f0109fa248ea4ff19538b3e99f0c5";
     };
   
     nativeBuildInputs = [
  -    # Pre-generated autoconf/automake files are outdated and fail
  -    # to detect libv4l & ffmpeg correctly.
  -    autoreconfHook
  -    intltool
       vala
     ];
   
  
positive.code:     "--${boolWt (jasper != null)}-jasper"
      "--without-graphviz"
      "--without-lua"
      "--${boolWt (ffmpeg != null)}-libavformat"
      "--${boolWt (v4l_lib != null)}-libv4l"
      "--${boolWt (lcms2 != null)}-lcms"
      "--without-libspiro"
      "--${boolWt (exiv2 != null)}-exiv2"
      "--without-exit2"
      "--without-umfpack"
      "--${boolWt (libtiff != null)}-libtiff"
      "--${boolWt (libwebp != null)}-webp"
  
negative.code:     babl
      cairo
      exiv2
      ffmpeg_3-4
      gdk-pixbuf
      gexiv2
      glib
  