Add location information when accessing already closed stackref

Author: markshannon

Objects/object.c

@@ -2984,7 +2984,7 @@ _Py_Dealloc(PyObject *op)
     destructor dealloc = type->tp_dealloc;
 #ifdef Py_DEBUG
     PyThreadState *tstate = _PyThreadState_GET();
-#ifndef Py_GIL_DISABLED
+#if !defined(Py_GIL_DISABLED) && !defined(Py_STACKREF_DEBUG)
     /* This assertion doesn't hold for the free-threading build, as
      * PyStackRef_CLOSE_SPECIALIZED is not implemented */
     assert(tstate->current_frame == NULL || tstate->current_frame->stackpointer != NULL);

Python/stackrefs.c

@@ -105,7 +105,7 @@ _Py_stackref_record_borrow(_PyStackRef ref, const char *filename, int linenumber
     PyInterpreterState *interp = PyInterpreterState_Get();
     TableEntry *entry = _Py_hashtable_get(interp->stackref_debug_table, (void *)ref.index);
     if (entry == NULL) {
-        _Py_FatalErrorFormat(__func__, "Invalid StackRef with ID %" PRIu64 "\n", (void *)ref.index);
+        _Py_FatalErrorFormat(__func__, "Invalid StackRef with ID %" PRIu64 " at %s:%d\n", (void *)ref.index, filename, linenumber);
     }
     entry->filename_borrow = filename;
     entry->linenumber_borrow = linenumber;