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:       (opensubdiv.override { inherit cudaSupport; })
        tbb
        makeWrapper
      ]
      ++ (if (!stdenv.isDarwin) then [
        libXi libX11 libXext libXrender
  
negative.code: , colladaSupport ? true, opencollada
  , makeWrapper
  , pugixml, SDL, Cocoa, CoreGraphics, ForceFeedback, OpenAL, OpenGL
  , embree
  }:
  
  with lib;
  