In 4.2, when exclude-unlisted-classes is true, hbm files are not detected. [1]

This got broken in 4.3 and is still broken in 5.0. [2]

[1] https://github.com/hibernate/hibernate-orm/blob/4.2/hibernate-entitymanager/src/main/java/org/hibernate/ejb/Ejb3Configuration.java#L829
[2] https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/boot/archive/scan/internal/StandardScanOptions.java#L23