Task.request is not celery.worker.request.Request (during task_prerun)

[flaeppe]

Task.request is typed like below

celery-types/celery-stubs/app/task.pyi

Lines 235 to 236 in af89436

	@property
	def request(self) -> Request: ...

With the following task_prerun receiver

@signals.task_prerun.connect
def task_prerun_receiver(*args: Any, **kwargs: Any) -> None:
    task: Task = kwargs["sender"]
    ...
    logger.info("task_prerun_receiver", task_request_dict=task.request.request_dict)

I'm getting at traceback like

Traceback (most recent call last):
  File "/app/venv/lib/python3.10/site-packages/celery/utils/dispatch/signal.py", line 276, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/app/src/myapp/celery/app.py", line 59, in task_prerun_receiver
    logger.info("task_prerun_receiver", task_request_dict=task.request.request_dict)
AttributeError: 'Context' object has no attribute 'request_dict'

Celery documents "Sender is the task object being executed"
Ref: https://docs.celeryq.dev/en/stable/userguide/signals.html#task-prerun

I thought task.request was a Request object, but at least in the case of a receiver on task_prerun it's rather an instance of celery.app.task.Context.