It seems like a very minor priority bug. Hibernate doesn't recognize Object in cyclic reference in a very bad designed relations architecture. Anyway it's a bug.

The detailed description with source code is here: https://github.com/Sergei-Rudenkov/jpa_fetching_investigations/
I attached zip with source code too.

I used:

• Java 1.8
• Spring boot 1.3.1.RELEASE
• Latest for time of writting Hibernate 5.2.4.Final
• Postgresql 9.4

I faced problem the same as OP in this question:
http://stackoverflow.com/questions/38874609/how-to-define-friendship-relationship-using-hibernate

References' dependencies are not trivial, and I would say Badly Designed, vialete sane DB normalization rules, I cannot say which one. Anyway it sounds like a bug against hibernate.

> All JPA providers should be able to cope with eager loading of cyclic relations. Any problem should mean you raise a bug against the JPA provider.

Reproduce the bug:

So I fixed the problem by adding LAZY. Initialization to make problem came up again switch it back to EAGER:

public class Member implements Serializable {
    //...
    @OneToMany(fetch = FetchType.EAGER, mappedBy = "requester")
    private Set[Friendship] friendRequests = new HashSet[Friendship]();
    @OneToMany(fetch = FetchType.EAGER, mappedBy = "friend")
    private Set[Friendship] friends = new HashSet[Friendship]();

Add then several rows to each table:

INSERT INTO member values(1, 'Aliaksei', 'Losyca', 'dvorik')
INSERT INTO member values(2, 'Siarzuk', 'Malinauka', 'kurik')

INSERT INTO friendship values(true, null, 'dvorik', 'kurik')