anchor.diff:        glew xorg.libX11 xorg.libXrandr xorg.libXxf86vm xorg.libXcursor
         xorg.libXinerama xorg.libXi
       ]
  -    ++ lib.optional (!stdenv.isDarwin) ocl-icd
  +    ++ lib.optional (openclSupport && !stdenv.isDarwin) ocl-icd
       ++ lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [OpenCL Cocoa CoreVideo IOKit AppKit AGL ])
       ++ lib.optional cudaSupport cudatoolkit;
   
  
positive.code:   meta = {
      description = "An Open-Source subdivision surface library";
      homepage = "http://graphics.pixar.com/opensubdiv";
      platforms = lib.platforms.unix;
      maintainers = [ lib.maintainers.eelco ];
      license = lib.licenses.asl20;
  
negative.code:       "-DGLEW_INCLUDE_DIR=${glew.dev}/include"
        "-DGLEW_LIBRARY=${glew.dev}/lib"
      ] ++ lib.optionals cudaSupport [
        "-DOSD_CUDA_NVCC_FLAGS=--gpu-architecture=${cudaArch}"
        "-DCUDA_HOST_COMPILER=${cudatoolkit.cc}/bin/cc"
      ] ++ lib.optionals (!openclSupport) [
        "-DNO_OPENCL=1"
      ];
  
    postInstall = "rm $out/lib/*.a";
  