Since Hibernate required a Javassist version significantly higher than what is included in WildFly, to run integration tests we bundled an "override" version of Javassist to use our version of Javassist rather than the one in WildFly.

The version in WildFly 11 is now slightly out of date compared to the one being used by Hibernate ORM but it appears to be compatible, so when running integration tests I'd switch to use the application server provided version as this avoids some trouble in JDK9 related tests.

Incidentally this also simplifies the packaging requirements of end users: they no longer need to explicitly exclude the javassist module from the server, so it's a good usability improvement.