https://bugs.gentoo.org/956566
https://github.com/wxWidgets/Phoenix/issues/2758
https://github.com/Python-SIP/sip/issues/77#issuecomment-2909587858
--- a/sipbuild/generator/instantiations.py
+++ b/sipbuild/generator/instantiations.py
@@ -463,3 +463,3 @@
     if klass.iface_file.module is None and superclass_name.is_simple:
-        superclass = _find_argument_value(superclass_name, p, symbol,
+        superclass = _find_argument_value(superclass_name.base_name, p, symbol,
                 tmpl_names, template, pm)