The logging package in python supports hierarchical logger names, e.g., foo.bar.baz. The beforementioned logger name [can] inherit settings from "foo" or "foo.bar". The changes made in 1a874a126a54fdc188cebd0c58579851c37d1814 unfortunately broke this capability, breaking application code in the process which handles filtering out specific names to specific log sinks; now all logging with dotted names goes to /var/log/messages . The strictness was relaxed in 3b4cc56e524ac947ba0e6571e2c455139c2839ec for PRI. Similar treatment needs to be applied for TAG as well. References: - https://docs.python.org/3/library/logging.html#logger-objects