anchor.diff:  }:
   
   let
  -  inherit (stdenv.lib)
  +  inherit (lib)
       optionals;
   
  -  version = "0.8.2";
  +  version = "0.9.0";
   in
   buildPythonPackage rec {
     name = "rebulk-${version}";
  
positive.code:   src = fetchPyPi {
      package = "rebulk";
      inherit version;
      sha256 = "8c09901bda7b79a21d46faf489d67d017aa54d38bdabdb53f824068a6640401a";
    };
  
    propagatedBuildInputs = [
  
negative.code: { stdenv
  , buildPythonPackage
  , fetchPyPi
  , lib
  
  , pytest-runner
  , regex
  