o = s.query(SomeClass).select(SomeClass.c.id==7817)[0]
o.attributes # Expunges fine without loading it. Breaks after loading or while eager-loading.
s.expunge(o)
Traceback (most recent call last):
File "example.py", line 330, in ?
s.expunge(o)
File "/home/alex/pydev/Sqlalchemy/trunk/sqlalchemy/orm/session.py", line 385, in expunge
self.uow._remove_deleted(c)
File "/home/alex/pydev/Sqlalchemy/trunk/sqlalchemy/orm/unitofwork.py", line 112, in _remove_deleted
del self.identity_map[obj._instance_key]
KeyError: (<class '__main__.SomeClass'>, (48931L, 1L), None)