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:   opencv3 = callPackage ../development/libraries/opencv/3.x.nix {
      enableCuda = config.cudaSupport or false;
      inherit (darwin.apple_sdk.frameworks) AVFoundation Cocoa QTKit VideoDecodeAcceleration;
    };
  
    # this ctl version is needed by openexr_viewers
  
negative.code:   digikam = libsForQt5.callPackage ../applications/graphics/digikam {
      inherit (plasma5) oxygen;
      inherit (kdeApplications) kcalcore;
      opencv3 = opencv3WithoutCuda;
    };
  
    displaycal = (newScope pythonPackages) ../applications/graphics/displaycal {};
  