anchor.diff:      stdenv = gcc7Stdenv;
       inherit (linuxPackages) nvidia_x11;
       opencv3 = opencv3WithoutCuda; # Used only for image loading.
  -    cudaSupport = pkgs.config.cudaSupport or false;
  +    cudaSupport = config.cudaSupport or false;
     };
   
     ecm = callPackage ../applications/science/math/ecm { };
  
positive.code: 
    libtorch-bin = callPackage ../development/libraries/science/math/libtorch/bin.nix {
      inherit (linuxPackages) nvidia_x11;
      cudaSupport = pkgs.config.cudaSupport or false;
    };
  
    behdad-fonts = callPackage ../data/fonts/behdad-fonts { };
  
negative.code:   tensor = libsForQt5.callPackage ../applications/networking/instant-messengers/tensor { };
  
    libtensorflow-bin = callPackage ../development/libraries/science/math/tensorflow/bin.nix {
      cudaSupport = config.cudaSupport or false;
      inherit (linuxPackages) nvidia_x11;
      cudatoolkit = cudatoolkit_10_0;
      cudnn = cudnn_cudatoolkit_10_0;
  