anchor.diff:    digikam = libsForQt5.callPackage ../applications/graphics/digikam {
       inherit (plasma5) oxygen;
       inherit (kdeApplications) kcalcore;
  +    opencv3 = opencv3WithoutCuda;
     };
   
     displaycal = (newScope pythonPackages) ../applications/graphics/displaycal {};
  
positive.code:     cudnnSupport = cudaSupport;
      inherit (linuxPackages) nvidia_x11;
      # Used only for image loading.
      opencv3 = self.opencv3.override {
        enableCuda = false;
      };
    };
  
    ecm = callPackage ../applications/science/math/ecm { };
  
negative.code:     cudaSupport = config.caffe.cudaSupport or config.cudaSupport or false;
      cudnnSupport = cudaSupport;
      # Used only for image loading.
      opencv3 = opencv3WithoutCuda;
    };
  
    caffe2 = callPackage ../development/libraries/science/math/caffe2 {
  