user1@localhost:~$ sudo journalctl -u snapd.autoimport.service
-- Logs begin at Tue 2017-09-19 18:38:02 UTC, end at Tue 2017-09-19 18:41:28 UTC. --
Sep 19 18:38:05 localhost.localdomain systemd[1]: Starting Auto import assertions from block devices...
Sep 19 18:38:05 localhost.localdomain snap[1072]: 2017/09/19 18:38:05.987339 cmd_auto_import.go:145: imported /run/snapd/auto-import/eulk7jViT1zg_BTzVtQJ_7lV9Kpb5q3N5UCJHgKQGoEdIfwm8iFZq6HzOsznsh8s.assert
Sep 19 18:38:05 localhost.localdomain snap[1072]: error: cannot create user: device already managed
Sep 19 18:38:05 localhost.localdomain systemd[1]: snapd.autoimport.service: Main process exited, code=exited, status=1/FAILURE
Sep 19 18:38:05 localhost.localdomain systemd[1]: Failed to start Auto import assertions from block devices.
Sep 19 18:38:05 localhost.localdomain systemd[1]: snapd.autoimport.service: Unit entered failed state.
Sep 19 18:38:05 localhost.localdomain systemd[1]: snapd.autoimport.service: Failed with result 'exit-code'.