anchor.diff:      psutil
     ];
   
  -  # leave build directory, so the installed library gets imported
  +  # for lz4.steam
  +  PYLZ4_EXPERIMENTAL = true;
  +
  +  # prevent local lz4 directory from getting imported as it lacks native extensions
     preCheck = ''
  -    pushd tests
  -  '';
  -
  -  postCheck = ''
  -    popd
  +    rm -r lz4
  +    export PYTHONPATH=$out/${python.sitePackages}:$PYTHONPATH
     '';
   
     meta = with lib; {
  
positive.code:     "lz4"
      "lz4.block"
      "lz4.frame"
    ];
  
    checkInputs = [
  
negative.code: , buildPythonPackage
  , fetchFromGitHub
  , pythonOlder
  , python
  
  # native inputs
  , pkgconfig
  