https://src.fedoraproject.org/rpms/python-pyqt6/blob/rawhide/f/py315.patch
--- a/qpy/QtCore/qpycore_pyqtslot.cpp
+++ b/qpy/QtCore/qpycore_pyqtslot.cpp
@@ -24,6 +24,13 @@
 #include "qpycore_pyqtslot.h"
 
 
+// PyWeakref_GetObject was removed from headers in Python 3.15 but is still
+// part of the stable ABI. Declare it here for Python 3.15+ compatibility.
+#if PY_VERSION_HEX >= 0x030f0000
+extern "C" PyObject* PyWeakref_GetObject(PyObject *ref);
+#endif
+
+
 // Create the slot for a callable.
 PyQtSlot::PyQtSlot(PyObject *callable, bool callable_is_method,
         const Chimera::Signature *slot_signature)