The C APIPyImport_AddModule() returns a borrowed reference using a special dance added by commit4db8988 of issue#86160:

PyObject*ref=PyWeakref_NewRef(mod,NULL);Py_DECREF(mod);if (ref==NULL) {returnNULL;        }mod=PyWeakref_GetObject(ref);Py_DECREF(ref);

Borrowed references are bad:

• "Functions must not return borrowed references" sayshttps://devguide.python.org/developer-workflow/c-api/index.html
• Unclear lifetimes of borrowed references capi-workgroup/problems#5

I proposed to:

• Add a newPyImport_AddModuleRef(const char *name) function, similar toPyImport_AddModule() but return astrong reference
• DeprecatePyImport_AddModule() andPyImport_AddModuleObject()

Linked PRs

• gh-105922: Add PyImport_AddModuleRef() function #105923
• gh-105922: Refactor PyRun_InteractiveOneObjectEx() #105925
• gh-105922: PyImport_AddModule() uses Py_DECREF() #105998
• gh-105922: Use PyImport_AddModuleRef() function #105999