anchor.diff:  , python
   , cudatoolkit
   , nvidia_x11
  +, gtest
   }:
   
   stdenv.mkDerivation rec {
  
positive.code:     cmake ../src -DCMAKE_INSTALL_PREFIX=$out \
                   -DCMAKE_BUILD_TYPE=Release \
                   -DOPENCL_ROOT=${cudatoolkit} \
    '';
  
    dontStrip = true; 
  
negative.code:     python
      cudatoolkit
      nvidia_x11
      gtest
    ]; 
  
    meta = with stdenv.lib; {
  