anchor.diff:  , libxslt
   , docbook_xsl
   , python3
  +, itstool
   }:
   
   stdenv.mkDerivation rec {
  
positive.code: { lib, stdenv
  , fetchFromGitHub
  , pkg-config
  , mono
  
negative.code:     libxslt
      docbook_xsl
      python3
      itstool
    ];
  
    preFixup = ''
  