yams #282697 can't define an attribute by subclassing RelationDefinition [validation pending]

some cubes rely on that ability, but it now breaks with:

  File "/home/jcr/src/cw/yams/reader.py", line 297, in fill_schema_from_namespace
    fill_schema(schema, erdefs, **kwargs)
  File "/home/jcr/src/cw/yams/reader.py", line 80, in fill_schema
    definition.expand_relation_definitions(erdefs, schema)
  File "/home/jcr/src/cw/yams/buildobjs.py", line 504, in expand_relation_definitions
    rdef._add_relations(defined, schema)
  File "/home/jcr/src/cw/yams/buildobjs.py", line 743, in _add_relations
    if self.formula is not None:
AttributeError: 'RelationDefinition' object has no attribute 'formula'
priorityimportant
typebug
done in0.40.1
load0.250
load left0.000
closed by#616c2bd144ea buildobjs: allow defining attributes by subclassing RelationDefinition again
patchbuildobjs: allow defining attributes by subclassing RelationDefinition again [applied]