python manage.py celery worker -l INFO必报这个错

环境：python3.6+django.2.0，是不是Django 版本太高了， 我看视频用的1.8

[2018-12-18 15:04:36,822: WARNING/MainProcess] /Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/billiard/__init__.py:321: RuntimeWarning: force_execv is not supported as the billiard C extension is not installed

  warnings.warn(RuntimeWarning(W_NO_EXECV))

[2018-12-18 15:04:37,099: INFO/MainProcess] Connected to redis://:**@127.0.0.1:6379/1

[2018-12-18 15:04:37,111: INFO/MainProcess] mingle: searching for neighbors

[2018-12-18 15:04:38,119: INFO/MainProcess] mingle: all alone

[2018-12-18 15:04:38,131: WARNING/MainProcess] /Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/djcelery/loaders.py:133: UserWarning: Using settings.DEBUG leads to a memory leak, never use this setting in production environments!

  warn('Using settings.DEBUG leads to a memory leak, never '

[2018-12-18 15:04:38,131: WARNING/MainProcess] celery@TesterCCdeMacBook-Pro.local ready.

[2018-12-18 15:04:39,732: ERROR/MainProcess] Unrecoverable error: AttributeError("'str' object has no attribute 'items'",)

Traceback (most recent call last):

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/worker/__init__.py", line 206, in start

    self.blueprint.start(self)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/bootsteps.py", line 123, in start

    step.start(parent)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/bootsteps.py", line 374, in start

    return self.obj.start()

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/worker/consumer.py", line 280, in start

    blueprint.start(self)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/bootsteps.py", line 123, in start

    step.start(parent)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/worker/consumer.py", line 884, in start

    c.loop(*c.loop_args())

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/celery/worker/loops.py", line 76, in asynloop

    next(loop)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/kombu/async/hub.py", line 340, in create_loop

    cb(*cbargs)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/kombu/transport/redis.py", line 1019, in on_readable

    self._callbacks[queue](message)

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/kombu/transport/virtual/__init__.py", line 534, in _callback

    self.qos.append(message, message.delivery_tag)

  File "/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/kombu/transport/redis.py", line 146, in append

    pipe.zadd(self.unacked_index_key, delivery_tag, time()) \

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/redis/client.py", line 2263, in zadd

    for pair in iteritems(mapping):

  File "/Development/virtualenv_workspace/py36dj2/lib/python3.6/site-packages/redis/_compat.py", line 123, in iteritems

    return iter(x.items())

AttributeError: 'str' object has no attribute 'items'