anchor.diff:          disabledModules = m.disabledModules or [];
           imports = m.require or [] ++ m.imports or [];
           options = {};
  -        config = mkMerge [ (removeAttrs m ["_file" "key" "disabledModules" "require" "imports"]) metaSet ];
  +        config = addMeta (removeAttrs m ["_file" "key" "disabledModules" "require" "imports"]);
         };
   
     applyIfFunction = key: f: args@{ config, options, lib, ... }: if isFunction f then
  
positive.code:           disabledModules = m.disabledModules or [];
            imports = m.imports or [];
            options = m.options or {};
            config = mkMerge [ (m.config or {}) metaSet ];
          }
      else
        { _file = m._file or file;
  
negative.code:   /* Massage a module into canonical form, that is, a set consisting
       of ‘options’, ‘config’ and ‘imports’ attributes. */
    unifyModuleSyntax = file: key: m:
      let addMeta = config: if m ? meta
        then mkMerge [ config { meta = m.meta; } ]
        else config;
      in
      if m ? config || m ? options then
        let badAttrs = removeAttrs m ["_file" "key" "disabledModules" "imports" "options" "config" "meta"]; in
  