Comment # 9 on bug 972394 from Matthias Klostermair

journalctl -b | grep profile-sync-daemon:

Apr 07 06:23:42 nohostname systemd[1385]: Started Timer for profile-sync-daemon
- 1Hour.
Apr 07 06:23:42 nohostname profile-sync-daemon[1440]: No status data could be
sent: $NOTIFY_SOCKET was not set
Apr 07 06:23:42 nohostname profile-sync-daemon[1440]: firefox sync successful