Workaround setuptools bug

Author: vstinner

tests/test_pythoncapi_compat_cext.c

@@ -2670,14 +2670,28 @@ static PySlot module_slots[] = {
     {0, 0, {0}, {0}}
 };
 
-#define INIT_FUNC CONCAT(PyModExport_, MODULE_NAME)
+#define EXPORT_FUNC CONCAT(PyModExport_, MODULE_NAME)
 
 PyMODEXPORT_FUNC
-INIT_FUNC(void)
+EXPORT_FUNC(void)
 {
     return module_slots;
 }
 
+#ifdef MS_WINDOWS
+#define INIT_FUNC CONCAT(PyInit_, MODULE_NAME)
+
+// Workaround for https://github.com/pypa/distutils/issues/387
+// https://docs.python.org/3.16/howto/abi3t-migration.html#module-export-hook
+PyMODINIT_FUNC
+INIT_FUNC(void)
+{
+    PyErr_SetString(PyExc_SystemError,
+                    "PyInit_* called for module with PyModExport_*");
+    return NULL;
+}
+#endif
+
 #else
 
 static PyModuleDef_Slot module_slots[] = {