This patch is generally useful to fix:
/tmp/ccEVEKCP.ltrans21.ltrans.o:<artificial>:function KirigamiPlugin::registerTypes(char const*)::{lambda(QQmlEngine*, QJSEngine*)#8}::_FUN(QQmlEngine*, QJSEngine*): error: undefined reference to 'Kirigami::TabletModeWatcher::self()'
It does not however fix the tablet mode itself, it justs make it past this specific error.