Qt 5.11 + Embedded Linux + QtVirtualKeyboard segmentation fault

  • Hello,

    Recently I want to use QML with Qtvirtualkeyboard, but I got "Segmentation fault" after I add "InputPanel" in the qml file, I'm not using Boot 2 QT device, is this the problem?

  • Moderators

    Run your app with a debugger - it will show you exactly where the crash happened.

    Not running Boot2Qt is not in itself a problem. Check the documentation on Qt Virtual Keyboard (it contains a guide on how to deploy and use it), make sure you have it installed/ compiled with your Qt version.

  • Hello,

    I'vd finish run my program with both desktop and arm in remote debut mode, but I cannot step into the process after enter engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    I also enabled the QT_DEBUG and QT_DEBUG_PLUGINS, the difference between both configuration is that the arm version stopped after load "libqtquicktemplates2plugin.so", the desktop version still loading following library:
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqgif.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqicns.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqico.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqjpeg.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqsvg.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqtga.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqtiff.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqwbmp.so"
    loaded library "/usr/local/Qt-5.11.1/plugins/imageformats/libqwebp.so"

    is the arm version crashed whiling loading libqgif.so?

    how can I know what happen inside the qml loading process?

    besides, my application runs correctly in both desktop and arm version without the "Input Panel" in the main.qml.

  • Moderators

    Do you have QtVirtualoKeyboard compiled in your ARM version of Qt?

  • Hello,
    Yes, the program loaded the plugin,

    QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt/plugins/platforminputcontexts/libqtvirtualkeyboardplugin.so"
    Found metadata in lib /usr/local/qt/plugins/platforminputcontexts/libqtvirtualkeyboardplugin.so, metadata=
        "IID": "org.qt-project.Qt.QPlatformInputContextFactoryInterface.5.1",
        "MetaData": {
            "Keys": [
        "className": "QVirtualKeyboardPlugin",
        "debug": false,
        "version": 330497
    Got keys from plugin meta data ("qtvirtualkeyboard")

  • Hello,

    I finally solved this problem. I compile both desktop and embedded version Qt from source, but the module was not compiled for version 5.11, QtQuickControls2, after finishing build this module and copy to the board, everything is OK.

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