Does this bug look familiar to anyone? import gc def bar(a): def foo(): return None x = a foo() class C:pass a = C() for i in range(20): print len(gc.get_referrers(a)) x = bar(a) On my Python, it just counts up. "a" gets more and more referrers and they are "cell" objects. If it is unknown, I'll submit a bug report unless someone fixes it before I get to it. ;) Paul Prescod