Comment 5 for bug 1638263

From a openstack/requirements POV we have a couple of options

https://review.openstack.org/#/c/392245/ (uncap amqp)
https://review.openstack.org/#/c/392135/ (cap kombu)

The first option is better as we're trying hard to *NOT* have caps where we can and it removes one :) However amqp was capped in https://review.openstack.org/#/c/322484/ because kombu itself required amqp < 2.0 https://github.com/celery/kombu/blob/3.0/requirements/default.txt

With the release of 4.0 we can see that the inverse is now true: https://github.com/celery/kombu/commit/b48a887a865971f98f3913c24daeb64e9db52527

So it seems to me that altering the cap on amqp is the correct solution here.

I've uploaded https://review.openstack.org/392354 to look into this