Notice: Undefined index: path in user_menu_breadcrumb_alter()

Notice: Undefined index: path in user_menu_breadcrumb_alter() (line 4086 of .../docroot/modules/user/user.module).

Although the path key is not required to render a breadcrumb, it is required by user_menu_breadcrumb_alter(), which is called by drupal_alter('menu_breadcrumb', $breadcrumbs_info, $breadcrumb_info_end);