d0644b040eb09e1ed147ff15e7c926c9e318cbca redefined signals from QWindow:

    void visibleChanged(bool arg);
    void visibilityChanged(QWindow::Visibility visibility);

Qt Virtual Keyboard's XCB input panel connects to QWindow::visibleChanged and this causes a warning about the signal being redefined. The workaround is to use the C++ syntax:

connect(focusWindow, &QWindow::visibleChanged, this, &XcbInputPanel::focusWindowVisibleChanged);