JPA Hibernate 5: OneToOne in nested Embeddable causes metamodel issue - jpa

Question

I have an entity:
#Entity
public class Test {
#Embedded
Content content;
// getters setters..
}
This contains an embedded class as you can see:
#Embeddable
public class Content {
#OneToOne
Person person;
#Embedded
Language language;
// getters setters..
}
This contains again an embeddable. 2 times nested embeddable
#Embeddable
public class Language {
String format;
#OneToOne
IdentifierCode identifierCode;
// getters setters..
}
When using the automatic schema generation feature of JPA all columns are generated in the correct way.
I use the #Data annotation on each #Entity and #Embeddable to generate getters, setters, constructors, etc..
When starting the application server (EAP 7), I notice this warning in the logs:
HHH015011: Unable to locate static metamodel field :
org.package.Language_#identifierCode; this may or may not indicate a
problem with the static metamodel
Indeed, when opening the metamodel class Language_; no identifierCode column reference is present:
#Generated(value = "org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor")
#StaticMetamodel(Language.class)
public abstract class Language_ {
public static volatile SingularAttribute<Language, String> format;
}
I don't see what I'm doing wroing. Is it not possible to use #OneToOne in a nested #Embeddable? The metamodel Content_ correctly generates the singular attribute for person!
It seems when using multiple nested embeddables, something goes wrong. When using only one level of embeddables, it works.
I tried other stuff:
Adding Access.Field on the class. Nothing happens.
Instantiation the #Embedded class, like #Embedded Language language = new Language(). Nothing happens.
Replaced the #OneToOne with #ManyToOne. Nothing happens.

Answer 1

This sounds like a bug in your JPA provider, which you should report to them.
The JPA provider I use (DataNucleus) creates a
public static volatile SingularAttribute<Language, mydomain.model.IdentifierCode> identifierCode;
One option you have is to just use the datanucleus-jpa-query.jar in your CLASSPATH to generate the static metamodel and use those generated classes with your existing provider, alternatively use it for persistence too.