can_non_root() can fail in multiple ways leaving the user to wonder
what happened and why. A user's only recourse is to post an email with
almost no diagnostic information on one of the mailing lists or in the
forums. Let's send some messages to syslog and stderr before bailing so
that the user has some idea why. This way we may be able to better
understand the nature of the problem and fix it.
MFC after: 3 days