anchor.diff:      protobuf = protobuf3_1;
       python-protobuf = python3Packages.protobuf3_1;
       # Used only for image loading.
  -    opencv3 = self.opencv3.override {
  -      enableCuda = false;
  -    };
  +    opencv3 = opencv3WithoutCuda;
     };
   
     cntk = callPackage ../applications/science/math/cntk rec {
  
positive.code:     cudaSupport = config.caffe.cudaSupport or config.cudaSupport or false;
      cudnnSupport = cudaSupport;
      # Used only for image loading.
      opencv3 = self.opencv3.override {
        enableCuda = false;
      };
    };
  
    caffe2 = callPackage ../development/libraries/science/math/caffe2 {
  
negative.code:   opencv3 = callPackage ../development/libraries/opencv/3.x.nix {
      enableCuda = config.cudaSupport or false;
      inherit (darwin.apple_sdk.frameworks) AVFoundation Cocoa QTKit VideoDecodeAcceleration;
    };
  
    opencv3WithoutCuda = opencv3.override {
      enableCuda = false;
    };
  
    # this ctl version is needed by openexr_viewers
  