TypeError: cannot concatenate 'str' and 'OptGroup' objects during Guru Meditation Report run

[melanie witt]

I noticed a trace in a recent tempest job run [1] like the following. From what I can tell, somehow rootkey here is an OptGroup object instead of the expected str.

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/guru_meditation_report.py", line 180, in handle_signal
    res = cls(version, frame).run()
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/guru_meditation_report.py", line 228, in run
    return super(GuruMeditation, self).run()
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/report.py", line 77, in run
    return "\n".join(six.text_type(sect) for sect in self.sections)
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/report.py", line 77, in <genexpr>
    return "\n".join(six.text_type(sect) for sect in self.sections)
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/report.py", line 102, in __str__
    return self.view(self.generator())
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/views/text/header.py", line 36, in __call__
    return six.text_type(self.header) + "\n" + six.text_type(model)
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/models/base.py", line 73, in __str__
    return self.attached_view(self_cpy)
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/views/text/generic.py", line 153, in __call__
    return "\n".join(serialize(model, None, -1))
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/views/text/generic.py", line 124, in serialize
    res.extend(serialize(root[key], key, indent + 1))
  File "/usr/local/lib/python2.7/dist-packages/oslo_reports/views/text/generic.py", line 113, in serialize
    res.append((self.indent_str * indent) + rootkey)
TypeError: cannot concatenate 'str' and 'OptGroup' objects
Unable to run Guru Meditation Report!

[1] http://logs.openstack.org/41/302341/5/check/gate-tempest-dsvm-full/f51065e/logs/screen-n-cpu.txt.gz?#_2016-04-08_21_08_08_994

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/305296

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/305296
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=acbf057d25390cf4adf48488908c9d5d35a55f10
Submitter: Jenkins
Branch: master

commit acbf057d25390cf4adf48488908c9d5d35a55f10
Author: Roman Podoliaka <email address hidden>
Date: Wed Apr 13 16:33:29 2016 +0300

    Fix generation of Guru Meditation Report

    Generation of a guru medidation report fails with TypeError when
    trying to serialize config group options. This is due to the fact,
    that I018c3a408a8903be8d006760994de6947fb91168 registers `barbican`
    options group incorrectly: an OptGroup instance is passed where a
    string name is expected (keystoneauth1 wraps the passed value
    into OptGroup unconditionally).

    A follow up change to oslo.config will make sure we fail early in
    case an incorrect value has been been passed to register_group().

    Change-Id: I4c57127c7bc0098000ad18ba7bab12fbc66d8ac0
    Closes-Bug: #1568208

[Davanum Srinivas (DIMS) (dims-v)]

This issue was fixed in the openstack/nova 14.0.0.0b1 development milestone.