anchor.diff: -{ lib, stdenv, buildPythonPackage, fetchPypi
  -, urllib3, certifi
  -, gevent, geventhttpclient, mock, fastimport
  -, git, glibcLocales }:
  +{ lib
  +, stdenv
  +, buildPythonPackage
  +, certifi
  +, fastimport
  +, fetchPypi
  +, gevent
  +, geventhttpclient
  +, git
  +, glibcLocales
  +, mock
  +, urllib3
  +}:
   
   buildPythonPackage rec {
  -  version = "0.20.15";
  +  version = "0.20.18";
     pname = "dulwich";
   
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "1248942fr12av2rkzpm2fq0qn6rajvv2lcgq65h8kby27qvp65zv";
  +    sha256 = "sha256-ATE4f5uZrsxprJhlWzkx8q1D2lPTpj4FD6Om1iYKxVQ=";
     };
   
     LC_ALL = "en_US.UTF-8";
  
positive.code: 
    doCheck = !stdenv.isDarwin;
  
    meta = with lib; {
      description = "Simple Python implementation of the Git file formats and protocols";
      longDescription = ''
  
negative.code:     '';
      homepage = "https://www.dulwich.io/";
      changelog = "https://github.com/dulwich/dulwich/blob/dulwich-${version}/NEWS";
      license = with licenses; [ asl20 gpl2Plus ];
      maintainers = with maintainers; [ koral ];
    };
  }
  