BND is a library that can wrap non-OSGized jars, dynamically populating its manifest with best-guess export and import packages. The hibernate-osgi tests use it to wrap a few dependencies, prior to test.

Gradle has an OSGi plugin, but it essentially supports adding OSGi entries in the manifest – and that's it. Even though the plugin includes BND, it doesn't allow direct, simple use. I requested it, but don't hold your breath:

http://forums.gradle.org/gradle/topics/add_simple_bnd_task_to_osgi_plugin

For now, use the new area created in HHH-8306 for a new plugin. hibernate-osgi currently includes bnd.jar and uses a JavaExec task. A plugin would be cleaner.

Consider contributing the plugin back to Gradle as a basis for their (hopeful) fix.