anchor.diff:  { stdenv
  +, buildPythonPackage
   , fetchPyPi
   , lib
  -, python
  -, setuptools
  -, unzip
   }:
   
   let
  
positive.code: 
    version = "0.30.0";
  in
  stdenv.mkDerivation rec {
    name = "wheel-${version}";
  
    src = fetchPyPi {
  
negative.code:     inherit version;
      sha256 = "9515fe0a94e823fd90b08d22de45d7bde57c90edce705b22f5e1ecf7e1b653c8";
    };
  
    meta = with lib; {
      description = "A built-package format for Python";
  