anchor.diff:        tidyr
       ]) ++ extraRPackages ++ rWrapper.recommendedPackages;
   
  -    checkPhase = ''
  -      pytest
  -    '';
  -
       nativeBuildInputs = [
         R # needed at setup time to detect R_HOME (alternatively set R_HOME explicitly)
       ];
  -
  -    patches = [
  -      # R_LIBS_SITE is used by the nix r package to point to the installed R libraries.
  -      # This patch sets R_LIBS_SITE when rpy2 is imported.
  -      ./rpy2-3.x-r-libs-site.patch
  -    ];
  -    postPatch = ''
  -      substituteInPlace 'rpy2/rinterface_lib/embedded.py' --replace '@NIX_R_LIBS_SITE@' "$R_LIBS_SITE"
  -    '';
   
       propagatedBuildInputs = [
         ipython
  
positive.code:       simplegeneric
      ];
  
      checkInputs = [
        pytest
      ];
  
      meta = {
  
negative.code: , cffi
  , tzlocal
  , simplegeneric
  , pytestCheckHook
  , extraRPackages ? []
  }:
  
  buildPythonPackage rec {
      version = "3.4.1";
      pname = "rpy2";
  
      disabled = isPyPy;
      src = fetchPypi {
        inherit version pname;
        sha256 = "1qnjjlgh6i31z45jykwd29n1336gq678fn9zw7gh0rv5d6sn0hv4";
      };
  
      patches = [
        # R_LIBS_SITE is used by the nix r package to point to the installed R libraries.
        # This patch sets R_LIBS_SITE when rpy2 is imported.
        ./rpy2-3.x-r-libs-site.patch
      ];
  
      postPatch = ''
        substituteInPlace 'rpy2/rinterface_lib/embedded.py' --replace '@NIX_R_LIBS_SITE@' "$R_LIBS_SITE"
        substituteInPlace 'requirements.txt' --replace 'pytest' ""
      '';
  
      buildInputs = [
        pcre
        lzma
        bzip2
        zlib
        icu
      ] ++ (with rPackages; [
        # packages expected by the test framework
        ggplot2
  