global name '_' is not defined in zun osc plugin

This error is on the gate:

2016-12-15 00:31:07.197 | + ./stack.sh:main:1055 : create_keystone_accounts
2016-12-15 00:31:07.201 | + lib/keystone:create_keystone_accounts:371 : local admin_project
2016-12-15 00:31:07.207 | ++ lib/keystone:create_keystone_accounts:372 : openstack project show admin -f value -c id
2016-12-15 00:31:09.391 | Traceback (most recent call last):
2016-12-15 00:31:09.391 | File "/usr/local/bin/openstack", line 11, in <module>
2016-12-15 00:31:09.391 | sys.exit(main())
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/openstackclient/shell.py", line 211, in main
2016-12-15 00:31:09.391 | return OpenStackShell().run(argv)
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/openstackclient/shell.py", line 46, in __init__
2016-12-15 00:31:09.391 | deferred_help=True)
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/osc_lib/shell.py", line 112, in __init__
2016-12-15 00:31:09.391 | deferred_help=True,
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/cliff/app.py", line 78, in __init__
2016-12-15 00:31:09.391 | self.parser = self.build_option_parser(description, version)
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/openstackclient/shell.py", line 57, in build_option_parser
2016-12-15 00:31:09.391 | parser = clientmanager.build_plugin_option_parser(parser)
2016-12-15 00:31:09.391 | File "/usr/local/lib/python2.7/dist-packages/openstackclient/common/clientmanager.py", line 124, in build_plugin_option_parser
2016-12-15 00:31:09.391 | parser = mod.build_option_parser(parser)
2016-12-15 00:31:09.392 | File "/opt/stack/new/python-zunclient/zunclient/osc/plugin.py", line 52, in build_option_parser
2016-12-15 00:31:09.392 | help=_("Container API version, default={0}"
2016-12-15 00:31:09.392 | NameError: global name '_' is not defined

Full log: http://logs.openstack.org/57/410457/4/check/gate-zun-devstack-dsvm-docker/42c4798/logs/devstacklog.txt.gz