anchor.diff:      luajit
       openexr
       suitesparse
  -  ] ++ lib.optional stdenv.isDarwin OpenCL;
  +  ] ++ lib.optionals stdenv.isDarwin [
  +    OpenCL
  +  ] ++ lib.optionals stdenv.cc.isClang [
  +    llvmPackages.openmp
  +  ];
   
     # for gegl-4.0.pc
     propagatedBuildInputs = [
  
positive.code: , glib
  , babl
  , libpng
  , cairo
  , libjpeg
  , librsvg
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "gegl";
    version = "0.4.40";
  
    outputs = [ "out" "dev" "devdoc" ];
    outputBin = "dev";
  
    src = fetchurl {
      url = "https://download.gimp.org/pub/gegl/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
      sha256 = "zd6A0VpJ2rmmFO+Y+ATIzm5M/hM5o8JAw08/tFQ2uF0=";
    };
  
    nativeBuildInputs = [
  