OpenStack DevStack Fail: installs keystoneauth1 2.12.2, then demands 2.16.0 or better

Question

This is on stable/newton, on Ubuntu 16.04 server.

Error message is:

 File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 859, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
ContextualVersionConflict: (keystoneauth1 2.12.2 (/usr/local/lib/python2.7/dist-packages), Requirement.parse('keystoneauth1>=2.16.0'), set(['glance-store']))
+inc/python:pip_install:1                  exit_trap

Before running ./stack.sh, from /opt/devstack as user stack:

stack@ubuntu-server-openstack:/opt/devstack$ pip list | ack keystoneauth1
DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
keystoneauth1 (2.16.0)
stack@ubuntu-server-openstack:/opt/devstack$

And after:

stack@ubuntu-server-openstack:/opt/devstack$ pip list | ack keystoneauth1
DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
keystoneauth1 (2.12.2)
stack@ubuntu-server-openstack:/opt/devstack$ 

I have also made sure to delete the pip cache rm -rf ~/.pip/cache, but there does not seem to be one for this user.

How can the version conflict be resolved?

Answer 1

I solved this by using the default Vagrant script to set up a new vm under VirtualBox, upon which devstack installed just fine (stable/newton). I then deleted the vm with the problem. I did not find the root cause of the misconfiguration with the python package versions.