mitsuhiko/babel — pull request #100 by astaric (2014-06-12 07:57:13+00:00)
Title: Add __copy__ and __deepcopy__ to LazyProxy.

When copy.copy or copy.deepcopy is used to copy LazyProxy, __init__ is never called and self._value is never set to None. Accessing it in self.value (which is used in __getattr__) triggers another call to __getattr__, resulting in endless recursion.