'module' object has no attribute 'add_arg'

[Stanislaw Pitucha]

When running 'nova list' using python-novaclient 2.16.0 or higher, I get only:

ᐅ nova list
ERROR: 'module' object has no attribute 'add_arg'

2.15.0 and lower work without issues. 2.16.0 and 2.17.0 fail with the same error.

Using python 2.7.6. Following packages are installed in a virtual env:

Babel (1.3)
cliff (1.4.4)
cmd2 (0.6.5.1)
d2to1 (0.2.11)
httplib2 (0.8)
iso8601 (0.1.10)
netaddr (0.7.10)
os-diskconfig-python-novaclient-ext (0.1.1)
os-networksv2-python-novaclient-ext (0.21)
oslo.config (1.1.1)
pbr (0.8.0)
pip (1.5.4)
prettytable (0.7.2)
pyparsing (1.5.7)
python-keystoneclient (0.3.2)
python-novaclient (2.16.0)
python-quantumclient (2.2.3)
pytz (2014.2)
rackspace-auth-openstack (1.0)
rackspace-novaclient (1.3)
rax-default-network-flags-python-novaclient-ext (0.1.3)
rax-scheduled-images-python-novaclient-ext (0.2.1)
requests (2.2.1)
setuptools (0.9.8)
simplejson (3.4.0)
six (1.6.1)
wsgiref (0.1.2)