I got report about messages in syslog:
quota_nld: Failed to find tty of user 0 to report warning to.
that abuse log. After long thinking I concluded the error message is useless (see attached patch for explanation, imagine cron job of a user who is lazy to clean his home), so I propose patch that reports this failure to stderr in foreground mode only (mainly for debugging purposes).
Anonymous
0001-Do-not-report-missing-utmp-record-to-syslog.patch
Thanks. I've added explanatory comment to the code and committed your patch.