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Author barry
Recipients Arfrever, alexandre.vassalotti, barry, josh.r, kitterma, nadeem.vawda, pitrou, python-dev, serhiy.storchaka
Date 2016-01-07.22:47:17
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
I added some debugging to the if(required) clause.  This is interesting:

basicsize 16
slotnames 0 basicsize 16
tp_basicsize 80 basicsize 16

tp_basicsize comes in at 16 bytes.  tp_dictoffset and tp_weaklistoffset must both be 0, and while slotnames is not Py_None, it must be adding 0 to the basicsize.  Since sizeof(PyObject *) can't be 0, it must mean that Py_SIZE(slotnames) is 0 (since they are multiplied).

But as you can see tp_basicsize is 80.  So essentially PyBaseObject_Type.tp_basicsize is 16 but obj->ob_type->tp_basicsize is 80, and that triggers the traceback.
Date User Action Args
2016-01-07 22:47:18barrysetrecipients: + barry, pitrou, alexandre.vassalotti, nadeem.vawda, Arfrever, kitterma, python-dev, serhiy.storchaka, josh.r
2016-01-07 22:47:18barrysetmessageid: <>
2016-01-07 22:47:18barrylinkissue22995 messages
2016-01-07 22:47:17barrycreate