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Author Oren Milman
Recipients Oren Milman
Date 2017-09-26.07:38:12
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Marked as misclassified Yes
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The following code causes a SystemError:
class BadMetaclass(type):
    def __prepare__(*args):

class Foo(metaclass=BadMetaclass):

This is because builtin___build_class__() assumes that __prepare__() returned a
mapping, and passes it to PyEval_EvalCodeEx(), which passes it to
_PyEval_EvalCodeWithName(), which passes it to _PyFrame_New_NoTrack(), which
raises the SystemError.

This issue seems related to #17421.
Date User Action Args
2017-09-26 07:38:12Oren Milmansetrecipients: + Oren Milman
2017-09-26 07:38:12Oren Milmansetmessageid: <>
2017-09-26 07:38:12Oren Milmanlinkissue31588 messages
2017-09-26 07:38:12Oren Milmancreate