I also tried your suggestion about setting the transient field from a non-transient field setter, but to no avail.
@sant0s You made me doubt, so I tried it. There were some errors in the snippet I gave you that prevented Hibernate ORM to boot, but once they are fixed, my solution works. Proof: hibernate-test-case-templates/search/hibernate-search-lucene at HHH-13052 · yrodiere/hibernate-test-case-templates · GitHub . Build this directory with mvn clean install, it will execute the tests, and the tests will pass.
Check that you added the @Access annotation to your ID class, and that you added the @java.persistence.Transient annotation on the getter for your transient field, in particular.