The ant plugin is unsupported at the moment. Please refer to http://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html#BytecodeEnhancement-enhancement on how to perform enhancement with maven / gradle plugins. That said, I'll be happy to review and integrate any contribution to the ant plugin you may have.

The current test infrastructure does not rely on any of the plugins, but on a classloader that performs the enhancing before loading a class. In any case, it's just plumbing ... it's always the same piece of code performing the enhancement.