Comment 1 for bug 1597697

The issue is reproducible only on custom 10.0 build with ubuntu xenial which probably contains newer version of oslo_log library.

All other fuel releases haven't been affected by it due to the fact that fuel-agent uses obsolete and stailed part of oslo_incubator's log.py which behaves in the following way:

The message will not be logged because a string formatting exception will occur. it just silently ignores the error and continues to work further with no visible side effects.