yams #237771 BadSchemaDefinition raised when using add_relation(SubjectRelation(...))) [open]

In my schema, I used to add a relation definition on a EntityType using add_relation(SubjectRelation(...))).
This lead to a BadSchemaDefinition.

Changing my schema by using a subclass of RelationDefinition to add the relation definition fixes the problem.

cubicweb 3.17.14
yams 0.38.1