https://github.com/pyside/pyside-setup/commit/33641ce807353f56d083f3ed1059bf67ce800e92

Affects python-3.14.4 as well for me (Alfred Wingate).

From 33641ce807353f56d083f3ed1059bf67ce800e92 Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Mon, 27 Apr 2026 22:02:54 +0200
Subject: [PATCH] libpyside: Fix tests bug_408/994 crashing in debug mode or
 when using Python 3.15

Python asserts about memory allocation for the metaObject attribute
string when not holding the GIL when connections  done in Qt C++ are
disconnected by the destructor, triggering
disconnectNotify()/metaObject(). To fix this, ensure the string is
created at initialization time.

The scenario of appears in ~QTextStream when wrapping it around
after another QIODevice after qtbase/e3c290e1947515992821e6bf97d74d65c9254271.

Task-number: PYSIDE-3221
Pick-to: 6.11 6.8
Change-Id: I76d0cf7567bfe073ad419b2f4b1d6617918bdb85
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>
--- a/sources/pyside6/libpyside/signalmanager.cpp
+++ b/sources/pyside6/libpyside/signalmanager.cpp
@@ -301,6 +301,14 @@ static PyObject *CopyCppToPythonPyObject(const void *cppIn)
 
 void SignalManager::init()
 {
+    // Force the metaObject attribute into existence. This fixes an
+    // exit crash (Python 3.15/allocation asserting since GIL is not held)
+    // when connections done in Qt C++ are disconnected by the destructor,
+    // triggering disconnectNotify()/metaObject().
+    // Note: SbkDeallocWrapperCommon() temporarily releases the GIL for
+    // legacy bug 500 (~QPrintDialog hanging).
+    [[maybe_unused]] auto *mo = metaObjectAttr();
+
     // Register Qt primitive typedefs used on signals.
     using namespace Shiboken;