reef-chrome-pfq has failed a sanity Skylab HW test:
https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8931376055177740512

The Skylab logs (https://chromeos-swarming.appspot.com/task?id=40d670b8cdeb1c10&refresh=10&show_raw=1) seem to suggest that the device needs repair:
skylab_swarming_worker: 2018/10/28 19:33:52 Got host event 'host_needs_repair', set host state to needs_repair

I kicked off a retry of the test (https://chromeos-swarming.appspot.com/task?id=40d6cd144e3fa010&refresh=10&show_raw=1) which failed with a different error, but I suspect this was user error on my part.