Exception messages don't get displayed correctly in test suite

[Johannes Erdfelt]

During the test suite, exception messages aren't displayed as formatted correctly. As an example:

======================================================================
ERROR: test_namespace_servers (nova.tests.integrated.test_xml.XmlTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/jenkins/workspace/nova/nova/tests/integrated/integrated_helpers.py", line 78, in setUp
    self._start_api_service()
  File "/home/jenkins/workspace/nova/nova/tests/integrated/integrated_helpers.py", line 83, in _start_api_service
    osapi = service.WSGIService("osapi")
  File "/home/jenkins/workspace/nova/nova/service.py", line 294, in __init__
    self.app = self.loader.load_app(name)
  File "/home/jenkins/workspace/nova/nova/wsgi.py", line 414, in load_app
    raise exception.PasteAppNotFound(name=name, path=self.config_path)
PasteAppNotFound: Could not load paste app '%(name)s' from %(path)s

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/709
Committed: http://github.com/openstack/nova/commit/82bef282c93a574ee5cfb2b34e0d8c077c2a7efe
Submitter: Jenkins
Branch: master

 status fixcommitted
 done

commit 82bef282c93a574ee5cfb2b34e0d8c077c2a7efe
Author: Johannes Erdfelt <email address hidden>
Date: Wed Sep 28 15:01:27 2011 +0000

    Accept message as sole argument to NovaException

    Fixes bug 860666

    Python nose will sometimes recreate an exception to add captured log
    information to the string representation of the exception. It assumes
    that it can do this by reinstantiating the class of the originally
    triggered exception with one argument, a new string description.
    NovaException, and some child classes, didn't work well with this
    scheme and would result in a further exception during formatting, which
    would result in an unformatted string being displayed.

    Change-Id: I7152cb7809fa1deb3986c127370f670fb2da342d