Intermittent test failure: allmydata.test.test_node.TestMissingPorts.test_listen_on_zero_with_host

[itamarst]

2021-08-19T21:00:37.3011896Z Traceback (most recent call last):
2021-08-19T21:00:37.3014752Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/allmydata/test/test_node.py", line 566, in test_listen_on_zero_with_host
2021-08-19T21:00:37.3016081Z     _tub_portlocation(config, None, None)
2021-08-19T21:00:37.3017651Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/twisted/trial/_synctest.py", line 355, in __exit__
2021-08-19T21:00:37.3018982Z     self._expectedName, reason.getTraceback()),
2021-08-19T21:00:37.3020515Z twisted.trial.unittest.FailTest: exceptions.TypeError raised instead of PortAssignmentRequired:
2021-08-19T21:00:37.3022040Z  Traceback (most recent call last):
2021-08-19T21:00:37.3023545Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/twisted/trial/_asynctest.py", line 112, in _run
2021-08-19T21:00:37.3025029Z     utils.runWithWarningsSuppressed, self._getSuppress(), method)
2021-08-19T21:00:37.3026977Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/twisted/internet/defer.py", line 151, in maybeDeferred
2021-08-19T21:00:37.3028085Z     result = f(*args, **kw)
2021-08-19T21:00:37.3029797Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/twisted/internet/utils.py", line 217, in runWithWarningsSuppressed
2021-08-19T21:00:37.3030997Z     result = f(*a, **kw)
2021-08-19T21:00:37.3032424Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/allmydata/test/test_node.py", line 566, in test_listen_on_zero_with_host
2021-08-19T21:00:37.3033655Z     _tub_portlocation(config, None, None)
2021-08-19T21:00:37.3034457Z --- <exception caught here> ---
2021-08-19T21:00:37.3035946Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/allmydata/test/test_node.py", line 566, in test_listen_on_zero_with_host
2021-08-19T21:00:37.3037193Z     _tub_portlocation(config, None, None)
2021-08-19T21:00:37.3038670Z   File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py27-coverage/lib/python2.7/site-packages/allmydata/node.py", line 809, in _tub_portlocation
2021-08-19T21:00:37.3039821Z     local_addresses = get_local_addresses_sync()
2021-08-19T21:00:37.3040862Z exceptions.TypeError: 'NoneType' object is not callable
2021-08-19T21:00:37.3041417Z 
2021-08-19T21:00:37.3041658Z 
2021-08-19T21:00:37.3042531Z allmydata.test.test_node.TestMissingPorts.test_listen_on_zero_with_host

[itamarst]

Originally seen in ​https://github.com/tahoe-lafs/tahoe-lafs/pull/1110 but seems unrelated to the changes there (I think).