You'll need to do a Couple Things to make it work. Our log4j is modified for the purpose of forwarding through the LogManager. So step one is, you'll have to make sure your module has a dependency on "org.jboss.logmanager" with 'services="import"' set.
Next, I believe you'll have to configure a LogManager-style logging.properties in your module as our log4j won't be configuring itself. Once you do these things you *should* get some output.