Comment 4 for bug 1549868

The error happens mostly when API is unresponsive and when ironicclient is used from some automation scripts/code, like rally.

to reproduce on MOS8:

1) deploy cluster with ironic
2) stop all ironic-api services on controllers to simulate non-responsive API
3) get Ironic API endpoint
   $ openstack catalog show baremetal
4) get Keystone token
   $ openstack token issue
5) issue following command
   $ ironic --ironic-url <public-ironic-endpoint-from-step-3> --os-auth-token <token-id-from-step-4> node-list

Expected:
meaningful HTTP-related error after some timeout

Actual:
almost immediate "global name '_' is not defined"

one can also prepend --debug to ironic command to see the actual request/response interchange