In 2010 cpython added
#include "structseq.h" into
Python.h see this commit.
I diffed pypy/module/cpyext/include/Python.h” and “cpython/Include/Python.h” and they most matched.
I don’t fully understanding the relation between PyPy and cpython and I apologize if this is a silly question, but should PyPy also move the include into Python.h?