Hope this helps, but I could solve problem in devstack ./stack.sh run by correcting my ~/.config/openstack/clouds.yaml not to refer to v2.0 to have openstackclient working. Otherwise one can "export OS_AUTH_URL=https://myhostname:5000" instead of OS_AUTH_URL=https://myhostname:5000/v2.0/ to have CLI working.
Hope this helps, but I could solve problem in devstack ./stack.sh run by correcting my ~/.config/ openstack/ clouds. yaml not to refer to v2.0 to have openstackclient working. Otherwise one can "export OS_AUTH_URL=https:/ /myhostname: 5000" instead of OS_AUTH_URL=https:/ /myhostname: 5000/v2. 0/ to have CLI working.