On 2018-06-21 11:22, Victor Stinner wrote:

https://www.python.org/dev/peps/pep-0580/#the-c-call-protocol

CCALL_VARARGS: cc_func(PyObject *self, PyObject *args)

If we add a new calling convention

This is not a *new* calling convention, it's the *existing* calling convention for METH_VARARGS. Obviously, we need to continue to support that.