Forcing enabling the GIL doesn't seem to work with PEP 793 initialization

[da-woods]

Bug report

Bug description:

#include <Python.h>

static int
examplemodule_exec(PyObject *module) {
 // Yes I know there's no error checking...
 PyObject *gil_enabled = PySys_GetObject("_is_gil_enabled");
 PyObject *result = PyObject_CallNoArgs(gil_enabled);
 printf("gil enabled: ");
 PyObject_Print(result, stdout, 0);
 printf("\n");
 Py_DECREF(result);
 return 0;
}

static PyModuleDef_Slot examplemodule_slots[] = {
 {Py_mod_name, "examplemodule"},
 {Py_mod_gil, Py_MOD_GIL_USED},
 {Py_mod_exec, (void*)examplemodule_exec},
 {0}
};

PyMODEXPORT_FUNC
PyModExport_examplemodule(void)
{
 return examplemodule_slots;
}

I believe that the code above should print "gil enabled: True". However when I run it on Python 3.15.0a2 freethreading it prints "gil enabled: False".

I don't believe this is an issue in the old style PyInit_ initialization.

CPython versions tested on:

3.15

Operating systems tested on:

Linux

Linked PRs

• gh-141780: Make PyModule_FromSlotsAndSpec enable GIL if needed  #141785

[da-woods]

@encukou

[encukou]

Thanks for the catch!

[da-woods]

Thanks