[2.5] Start-up - builtins.OSError: [Errno 9] Bad file descriptor

2018-09-28 01:39:41 maasserver.listener: [info] Listening for database notifications.
2018-09-28 01:39:41 maasserver.ipc: [info] Worker pid:11282 IPC connected.
2018-09-28 01:39:41 maasserver.ipc: [info] Worker pid:11282 opened RPC listener on port:5253.
2018-09-28 01:39:41 -: [critical] Unhandled Error
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1442, in gotResult
     _inlineCallbacks(r, g, deferred)
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
     result = g.send(result)
   File "/usr/lib/python3/dist-packages/maasserver/webapp.py", line 268, in privilegedStartService
     super(WebApplicationService, self).privilegedStartService()
   File "/usr/lib/python3/dist-packages/twisted/application/internet.py", line 360, in privilegedStartService
     self._waitingForPort = self.endpoint.listen(self.factory)
 --- <exception caught here> ---
   File "/usr/lib/python3/dist-packages/twisted/internet/endpoints.py", line 1235, in listen
     self._setNonBlocking(self.fileno)
   File "/usr/lib/python3/dist-packages/twisted/internet/fdesc.py", line 25, in setNonBlocking
     flags = fcntl.fcntl(fd, fcntl.F_GETFL)
 builtins.OSError: [Errno 9] Bad file descriptor

2018-09-28 01:39:42 -: [critical] Unhandled Error
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1442, in gotResult
     _inlineCallbacks(r, g, deferred)
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
     result = g.send(result)
   File "/usr/lib/python3/dist-packages/maasserver/webapp.py", line 268, in privilegedStartService
     super(WebApplicationService, self).privilegedStartService()
   File "/usr/lib/python3/dist-packages/twisted/application/internet.py", line 360, in privilegedStartService
     self._waitingForPort = self.endpoint.listen(self.factory)
 --- <exception caught here> ---
   File "/usr/lib/python3/dist-packages/twisted/internet/endpoints.py", line 1235, in listen
     self._setNonBlocking(self.fileno)
   File "/usr/lib/python3/dist-packages/twisted/internet/fdesc.py", line 25, in setNonBlocking
     flags = fcntl.fcntl(fd, fcntl.F_GETFL)
 builtins.OSError: [Errno 9] Bad file descriptor

2018-09-28 01:39:42 -: [critical] Unhandled Error
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1442, in gotResult
     _inlineCallbacks(r, g, deferred)
   File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
     result = g.send(result)
   File "/usr/lib/python3/dist-packages/maasserver/webapp.py", line 268, in privilegedStartService
     super(WebApplicationService, self).privilegedStartService()
   File "/usr/lib/python3/dist-packages/twisted/application/internet.py", line 360, in privilegedStartService
     self._waitingForPort = self.endpoint.listen(self.factory)
 --- <exception caught here> ---
   File "/usr/lib/python3/dist-packages/twisted/internet/endpoints.py", line 1235, in listen
     self._setNonBlocking(self.fileno)
   File "/usr/lib/python3/dist-packages/twisted/internet/fdesc.py", line 25, in setNonBlocking
     flags = fcntl.fcntl(fd, fcntl.F_GETFL)
 builtins.OSError: [Errno 9] Bad file descriptor

Full log in:
http://10.245.136.4:8080/job/maas-bionic-master-git/95/artifact/results/artifacts/maas-logs/var/log/maas/regiond.log