code: function (evt) {
                  var data = getScriptData(evt);
                  if (!hasPathFallback(data.id)) {
                      var parents = [];
                      eachProp(registry, function(value, key) {
                          if (key.indexOf('_@r') !== 0) {
                              each(value.depMaps, function(depMap) {
                                  if (depMap.id === data.id) {
                                      parents.push(key);
                                      return true;
                                  }
                              });
                          }
                      });
                      return onError(makeError('scripterror', 'Script error for "' + data.id +
                                               (parents.length ?
                                               '", needed by: ' + parents.join(', ') :
                                               '"'), evt, [data.id]));
                  }
              }
docs: Callback for script errors.