anchor.diff:    lib = pkgs.lib;
   
     # Remove invisible and internal options.
  -  optionsList = lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList options);
  +  optionsListVisible = lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList options);
   
     # Replace functions by the string <function>
     substFunction = x:
  
positive.code:   prefixesToStrip = map (p: "${toString p}/") ([ ../../.. ] ++ extraSources);
    stripAnyPrefixes = lib.flip (lib.fold lib.removePrefix) prefixesToStrip;
  
    # Convert the list of options into an XML file.
    optionsXML = builtins.toFile "options.xml" (builtins.toXML optionsList');
  
    optionsDocBook = runCommand "options-db.xml" {} ''
      optionsXML=${optionsXML}
  
negative.code:       mkdir -p $dst
  
        cp ${builtins.toFile "options.json" (builtins.unsafeDiscardStringContext (builtins.toJSON
          (builtins.listToAttrs (map (o: { name = o.name; value = removeAttrs o ["name" "visible" "internal"]; }) optionsList))))
        } $dst/options.json
  
        mkdir -p $out/nix-support
  