(gdb) where
#0  QXcbGlxWindow::createVisual() (this=0x5555556aaa20)
    at qtbase/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxwindow.cpp:31
#1  0x00007ffff220f09c in QXcbWindow::create() (this=0x5555556aaa20)
    at qtbase/src/plugins/platforms/xcb/qxcbwindow.cpp:309
#2  0x00007ffff21e4f62 in QXcbIntegration::createPlatformWindow(QWindow*) const
    (this=0x5555555aed10, window=0x555555712b80)
    at qtbase/src/plugins/platforms/xcb/qxcbintegration.cpp:205
#3  0x00007ffff66fbefa in QWindowPrivate::create(bool, unsigned long long)
    (this=0x55555569e270, recursive=false, nativeHandle=0)
    at qtbase/src/gui/kernel/qwindow.cpp:520
#4  0x00007ffff66fc34e in QWindow::create() (this=0x555555712b80)
    at qtbase/src/gui/kernel/qwindow.cpp:649
#5  0x00007ffff72ff2bc in QWidgetPrivate::create() (this=0x55555577f750)
    at qtbase/src/widgets/kernel/qwidget.cpp:1315
#6  0x00007ffff72fe8cc in QWidget::create(unsigned long long, bool, bool)
    (this=0x7fffffffddb0, window=0, initializeWindow=true, destroyOldWindow=true)
    at qtbase/src/widgets/kernel/qwidget.cpp:1179
#7  0x00007ffff73190e3 in QWidget::setParent(QWidget*, QFlags<Qt::WindowType>)
    (this=0x5555557a7420, parent=0x7fffffffddb0, f=...)
    at qtbase/src/widgets/kernel/qwidget.cpp:10708
#8  0x00007ffff72fdd45 in QWidgetPrivate::init(QWidget*, QFlags<Qt::WindowType>)
    (this=0x55555576d800, parentWidget=0x7fffffffddb0, f=...)
    at qtbase/src/widgets/kernel/qwidget.cpp:995
#9  0x00007ffff72fd59b in QWidget::QWidget(QWidgetPrivate&, QWidget*, QFlags<Qt::WindowType>) (this=0x5555557a7420, dd=..., parent=0x7fffffffddb0, f=...)
    at qtbase/src/widgets/kernel/qwidget.cpp:871
#10 0x00007ffff7be1e7a in QOpenGLWidget::QOpenGLWidget(QWidget*, QFlags<Qt::WindowType>)
    (this=0x5555557a7420, parent=0x7fffffffddb0, f=...)
    at qtbase/src/openglwidgets/qopenglwidget.cpp:960
#11 0x000055555556a1dc in Window::insertOpenGLWidget() (this=0x7fffffffddb0)
    at /opt/qwt/qwt1/examples/refreshtest/main.cpp:17