Comment 5 for bug 1579157

For me, this was due to os-networksv2-python-novaclient-ext.

sudo pip uninstall os-networksv2-python-novaclient-ext

How I found out:

I was using the python-openstackclient, but it might show up the same using just novaclient.

openstack --debug server list

Which showed at the bottom of the output:

  File "/Library/Python/2.7/site-packages/os_networksv2_python_novaclient_ext.py", line 16, in <module>
    from novaclient.openstack.common import cliutils as utils
ImportError: No module named openstack.common

Sure enough:

$ pip freeze | grep ext
os-networksv2-python-novaclient-ext==0.25

So, again, I ran this to fix it:

sudo pip uninstall os-networksv2-python-novaclient-ext