Jon Pretty

Wasn't sure if you meant clients to be just "users of library X"...

Anyhow, do you not think it's a problem having logging configured in some uncertain place you can't debug like code?

I'm imagining an implicit which could either handle logging itself, or delegate that to some other specific config.

I sympathise with the sentiment, but to me that is not principled. Logging is monitoring is an integration concern.

Therefore it is validated by developers (debugging) and CI tests / CD ops.

But as a developer I'd still like to see the logs without doing any integration. A one-line implicit seems a good way.

… then you cannot deploy those very same bits into production without the implicit becoming isomorphic to logback.xml

But difference is that logback.xml is not a known authority on conf. Classpath order and and JVM params can obfuscate.