Traceback (most recent call last):
  File "/usr/lib64/python2.6/runpy.py", line 122, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib64/python2.6/runpy.py", line 34, in _run_code
    exec code in run_globals
  File "/usr/lib/python2.6/site-packages/virtualenvwrapper/hook_loader.py", line 16, in <module>
    from stevedore import ExtensionManager
  File "/usr/lib/python2.6/site-packages/stevedore/__init__.py", line 23, in <module>
    LOG.addHandler(logging.NullHandler())
AttributeError: 'module' object has no attribute 'NullHandler'