About 3 hours ago a new version of Pip was released to the pypi site.

Tox jobs which pick up that version of pip will likely fail to install their dependencies.

Docker image jobs that are using loci (which uses pip) have also been observed to fail.

I don’t know what the fix is, I assume many python users in many projects will be impacted.

If you see an error with a signature like this, you’ve hit the problem

Exception:

Traceback (most recent call last):

File "/var/lib/openstack/lib/python2.7/site-packages/pip/_internal/cli/base_command.py", line 176, in main

status = self.run(options, args)

File "/var/lib/openstack/lib/python2.7/site-packages/pip/_internal/commands/install.py", line 346, in run

session=session, autobuilding=True

File "/var/lib/openstack/lib/python2.7/site-packages/pip/_internal/wheel.py", line 848, in build

assert building_is_possible

AssertionError