anchor.diff: -{ lib, stdenv, fetchgit, python, pythonPackages, makeWrapper }:
  +{ lib, stdenv, fetchgit, python3Packages, makeWrapper }:
   
   stdenv.mkDerivation {
   
  
positive.code: 
    nativeBuildInputs = [ makeWrapper ];
  
    propagatedBuildInputs = with pythonPackages; [ requests vobject lxml ];
  
    doCheck = false; # no test
  
  
negative.code:     mkdir -p $out/bin
      cp $src/carddav-util.py $out/bin
  
      pythondir="$out/lib/${python3Packages.python.sitePackages}"
      mkdir -p "$pythondir"
      cp $src/carddav.py "$pythondir"
    '';
  