anchor.diff:      ++ optional cudaSupport cudatoolkit
       ++ optional colladaSupport opencollada;
   
  -  postPatch =
  -    if stdenv.isDarwin then ''
  +  postPatch = ''
  +    # allow usage of dynamically linked embree
  +    rm build_files/cmake/Modules/FindEmbree.cmake
  +  '' +
  +    (if stdenv.isDarwin then ''
         : > build_files/cmake/platform/platform_apple_xcode.cmake
         substituteInPlace source/creator/CMakeLists.txt \
           --replace '${"$"}{LIBDIR}/python' \
  
positive.code:                   'set(OPENEXR_INCLUDE_DIRS "${openexr.dev}/include/OpenEXR") #'
      '' else ''
        substituteInPlace extern/clew/src/clew.c --replace '"libOpenCL.so"' '"${ocl-icd}/lib/libOpenCL.so"'
      '';
  
    cmakeFlags =
      [
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "blender";
    version = "2.90.0";
  
    src = fetchurl {
      url = "https://download.blender.org/source/${pname}-${version}.tar.xz";
      sha256 = "08qkvgdfrqh4ljqw5m64bbki1dsfcs4xnwzq6829z3ddhiwrxw84";
    };
  
    patches = lib.optional stdenv.isDarwin ./darwin.patch;
  