Comment 2 for bug 1401042

eventually during functional tests run you can find this:

Captured stderr:
~~~~~~~~~~~~~~~~
    Traceback (most recent call last):
      File "/usr/lib/python2.7/site-packages/eventlet/hubs/hub.py", line 455, in fire_timers
        timer()
      File "/usr/lib/python2.7/site-packages/eventlet/hubs/timer.py", line 58, in __call__
        cb(*args, **kw)
      File "/usr/lib/python2.7/site-packages/eventlet/greenthread.py", line 212, in main
        result = function(*args, **kwargs)
      File "neutron/openstack/common/lockutils.py", line 272, in inner
        return f(*args, **kwargs)
      File "neutron/agent/linux/external_process.py", line 273, in _check_child_processes
        for service_id in self._process_managers:
    RuntimeError: dictionary changed size during iteration