I just upgraded to 3.1.2 on Mavericks (with pythonbrew running python 2.7.2) and get this when I run the following command:
celery worker -A xxxxx -l info

[2013-11-12 22:42:55,499: ERROR/MainProcess] Unrecoverable error: TypeError('unpack_from() argument 1 must be string or read-only buffer, not memoryview',)
Traceback (most recent call last):
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/worker/init.py", line 208, in start
self.blueprint.start(self)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/bootsteps.py", line 127, in start
step.start(parent)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/bootsteps.py", line 378, in start
return self.obj.start()
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/worker/consumer.py", line 271, in start
blueprint.start(self)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/bootsteps.py", line 127, in start
step.start(parent)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/worker/consumer.py", line 766, in start
c.loop(_c.loop_args())
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/worker/loops.py", line 72, in asynloop
next(loop)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/kombu/async/hub.py", line 333, in create_loop
cb(_cbargs)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/concurrency/asynpool.py", line 248, in on_result_readable
next(it)
File "/Users/xxxx/.pythonbrew/venvs/Python-2.7.2/xxxx/lib/python2.7/site-packages/celery/concurrency/asynpool.py", line 202, in _recv_message
body_size, = unpack_from('>i', bufv)
TypeError: unpack_from() argument 1 must be string or read-only buffer, not memoryview