Project capturing defect available at https://github.com/wastevens/HibernateComparableDefect

When an entity is Comparable, and the compareTo method is directly using lambdas, a java.lang.reflect.GenericSignatureFormatError is generated while trying to create the EntityManager. (The full stack trace is attached)

I have NOT found this error manifest when lambdas are used elsewhere within the entity, nor when all Lambdas are first assigned to a local instance variable.