The function below is the workaround I plan to use based on the undocumented-but-public Thread attributes that relate to the task queue (it's essentially just a combination of Queue.join() with the existing structure of the Queue.get() implementation):

  def join_queue(q, timeout=None):
      q.all_tasks_done.acquire()
      try:
          if timeout is None:
              while q.unfinished_tasks:
                  self.all_tasks_done.wait()
          elif timeout < 0:
              raise ValueError("'timeout' must be a positive number")
          else:
              endtime = _time() + timeout
              while q.unfinished_tasks:
                  remaining = endtime - _time()
                  if remaining <= 0.0:
                      raise Pending
                  self.all_tasks_done.wait(remaining)
      finally:
          q.all_tasks_done.release()