Hello,
I have discovered that the declarations of PPyDescrObject and its descendants are not aligned with the current state of descrobject.h in Python 3.3+. The structure was extended in commit python/cpython@9d57481 . A patch is attached. I am also attaching a tiny patch to add PyGetSetDescr_Type declaration.

Best regards,
Joe

0001-reflect-PyDescr_COMMON-change-made-to-Python-3.3.patch
0001-add-PyGetSetDescr_Type.patch