I'm unsure if this is a packaging error or a misunderstanding by me.

I'm trying to link a binary on windows with Py_LIMITED_API set. According to https://www.python.org/dev/peps/pep-0384/#linkage I _think_ I'm supposed to be linking against python3.lib (instead of python39.lib).

However my build fails because the PyObject_CallNoArgs symbol is not present in python3.lib

I see that the symbol is indeed present in python39.lib

Is this a misunderstanding on my part? I was under the impression that python3.lib will only contain symbols available in the limited api, and that (since 3.9) PyObject_CallNoArgs is part of the limited api.

This looks like a bug to me. While https://github.com/python/cpython/commit/2ff58a24e8a1c7e290d025d69ebaea0bbead3b8c added it to the header, it did not add it to https://github.com/python/cpython/blob/master/PC/python3dll.c which is required.

Yeah, this will be our fault.

Someone is looking into automatically generating the .def file so that this stops happening. Last time we tried that there was a lot of pushback because "too many APIs will become stable", but this time I think we're just going to force those devs to care for their APIs properly.

(I'm blanking right now on who was working on this... anyone remember?)

commit fcc6935384b933fbe1a1ef659ed455a3b74c849a
Author: Victor Stinner <vstinner@python.org>
Date:   Wed Dec 16 15:08:23 2020 +0100

    Add symbols of the stable ABI to python3dll.c (GH-23598)
    
    Add the following symbols to python3dll.c:
    
    * PyFrame_GetCode (bpo-40421)
    * PyFrame_GetLineNumber (bpo-40421)
    * PyModule_AddObjectRef (bpo-1635741)
    * PyObject_CallNoArgs (bpo-37194)
    * PyThreadState_GetFrame (bpo-39947)
    * PyThreadState_GetID (bpo-39947)
    * PyThreadState_GetInterpreter (bpo-39947)

I backported the change manually to 3.9: PR 23801.

Thanks David Hewitt for the bug report, and Zackery Spytz for your fix!

3.9 fix:

commit 166286849048eccadecf02b242dbc4042b780944
Author: Victor Stinner <vstinner@python.org>
Date:   Wed Dec 16 22:41:47 2020 +0100

    Add symbols of the stable ABI to python3dll.c (GH-23598) (GH-23801)
    
    Add the following symbols to python3dll.c:
    
    * PyFrame_GetCode (bpo-40421)
    * PyFrame_GetLineNumber (bpo-40421)
    * PyObject_CallNoArgs (bpo-37194)
    * PyThreadState_GetFrame (bpo-39947)
    * PyThreadState_GetID (bpo-39947)
    * PyThreadState_GetInterpreter (bpo-39947)
    
    (cherry picked from commit fcc6935384b933fbe1a1ef659ed455a3b74c849a)