anchor.diff:  { lib
   , fetchFromGitHub
  -, python2Packages
  +, python3
   , asciidoc
   , cacert
   , docbook_xsl
  
positive.code:   # Test requires credentials
    doCheck = false;
  
    meta = with lib; {
      description = "Synchronize emails between two repositories, so that you can read the same mailbox from multiple computers";
      homepage = "http://offlineimap.org";
  
negative.code: , libxslt
  }:
  
  python3.pkgs.buildPythonApplication rec {
    pname = "offlineimap";
    version = "8.0.0";
  
    src = fetchFromGitHub {
      owner = "OfflineIMAP";
      repo = "offlineimap3";
      rev = "v${version}";
      sha256 = "0y3giaz9i8vvczlxkbwymfkn3vi9fv599dy4pc2pn2afxsl4mg2w";
    };
  
    nativeBuildInputs = [
  