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

https://pypi.org/project/pip/19.0/

 

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

 

Al