Error in long-running repeater

[tacaswell]

This may be related to restarting my network a few time / putting the laptop to sleep /

ERROR:asyncio:Exception in callback _SelectorDatagramTransport._read_ready()
handle: <Handle _SelectorDatagramTransport._read_ready()>
Traceback (most recent call last):
  File "/home/tcaswell/mc3/envs/dd36/lib/python3.6/asyncio/events.py", line 126, in _run
    self._callback(*self._args)
  File "/home/tcaswell/mc3/envs/dd36/lib/python3.6/asyncio/selector_events.py", line 1078, in _read_ready
    self._protocol.datagram_received(data, addr)
  File "caproto/examples/repeater.py", line 21, in datagram_received
    command = self.broadcaster.next_command()
  File "/home/tcaswell/src/bnl/epics/caproto/caproto/_hub.py", line 427, in next_command
    command = self._parsed_commands.popleft()
IndexError: pop from an empty deque