Description of problem:

Stack trace when cert file missing:

[mulhern@dhcp-25-209 ~]$ bkr whoami
Traceback (most recent call last):
  File "/usr/bin/bkr", line 9, in <module>
    load_entry_point('bkr.client==22.1', 'console_scripts', 'bkr')()
  File "/usr/lib/python2.7/site-packages/bkr/client/main.py", line 72, in main
    return cmd.run(*cmd_args, **cmd_opts.__dict__)
  File "/usr/lib/python2.7/site-packages/bkr/client/commands/cmd_whoami.py", line 56, in run
    self.set_hub(**kwargs)
  File "/usr/lib/python2.7/site-packages/bkr/client/__init__.py", line 71, in set_hub
    proxy_user=proxy_user)
  File "/usr/lib/python2.7/site-packages/bkr/client/command.py", line 279, in set_hub
    self.hub = HubProxy(conf=self.conf, auto_login=auto_login)
  File "/usr/lib/python2.7/site-packages/bkr/common/hub.py", line 57, in __init__
    ssl_context.load_verify_locations(cafile=self._conf['CA_CERT'])
IOError: [Errno 2] No such file or directory
Exception AttributeError: AttributeError("'HubProxy' object has no attribute '_transport'",) in <bound method HubProxy.__del__ of <bkr.common.hub.HubProxy object at 0x7f45c09a6410>> ignored


Version-Release number of selected component (if applicable):

22.1

How reproducible:

Always.

Steps to Reproduce:
1. Don't actually have a file corresponding to CA_CERT variable in comfig.
2. > bkr whoami
3. Observe stack trace.

Actual results:

Stack trace.

Expected results:

Something a little more confidence inspiring and perhaps more informative. No AttributeError.

Additional info:

Note the AttributeError...it seems like the HubProxy object is not fully constructed, so the __del__ method fails. Maybe necessary to be more conservative there.