DBus: Sending a QVariantMap with null QVariant can crash the application

QDBusMarshaller: cannot add a null QDBusVariant
dbus[330030]: Array or variant type requires that type variant be written, but end_dict_entry was written.
The overall signature expected here was 'a{sv}' and we are on byte 3 of that signature.
  D-Bus not built with -rdynamic so unable to print a backtrace

#include <QCoreApplication>
#include <QDBusConnection>
#include <QDBusMessage>

using namespace Qt::StringLiterals;

static const QString busName = u"org.example.MyInterface"_s;
static const QString path = u"/org/example/MyInterface"_s;

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
    QMetaObject::invokeMethod(&app, [&app]{
        QDBusMessage message = QDBusMessage::createMethodCall(busName, path, busName, u"SetParams"_s);
        message << QVariantMap{{u"a"_s, QVariant()}};
        QDBusConnection::sessionBus().call(message);
        app.quit();
    }, Qt::QueuedConnection);
    return app.exec();
}