.. efun:: mixed query_notify_fail()
  mixed query_notify_fail(int flag)

  If :arg:`flag` is not given or 0: return the string or closure which was last set as error message for this command (with :efun:`notify_fail`).

  If :arg:`flag` is given and 1: return the object which issued the last :efun:`notify_fail`.

  If nothing was set yet, return 0.

  :history 3.2.7 introduced:
  :history 3.2.8 changed: added the :arg:`flag` parameter.

  .. seealso:: :efun:`add_action`, :efun:`query_verb`, :efun:`query_command`, :efun:`notify_fail`, :overview:`hook`