anchor.diff:        else head v
       ) list;
   
  -  rename = statusTemplate: from: to: with pkgs.lib;
  +  rename = statusTemplate: from: to:
       let
         status = statusTemplate from to;
         setTo = setAttrByPath (splitString "." to);
  
positive.code:       abort "Deprecated option `${from}' is defined instead of `${to}'.";
    };
  
  
    zipModules = list: with pkgs.lib;
      zipAttrsWith (n: v:
        if tail v != [] then
          if n == "_type" then (head v)
  
negative.code:       fromOf = attrByPath (splitString "." from)
          (abort "Internal error: option `${from}' should be declared.");
      in
        [ { options = setFrom (mkOption {
              description = "${status.name} of <option>${to}</option>.";
              apply = x: status.msg.use (toOf config);
              visible = false;
            });
          }
          { options = setTo (mkOption {
              extraConfigs =
                let externalDefs = (fromOf options).definitions; in
                if externalDefs == [] then []
                else map (def: def.value) (status.msg.define externalDefs);
            });
          }
        ];
  
  in zipModules ([]
  
  