Qt Quick with cmake fails on Linux

michal.19937

Hello,
I have a problem - when I build and run a Qt Quick app on Linux Mint 22 no window appears and some Qt metadata is printed to the console. On Windows 11 the same code works though.
The metadata:

michal@Mint-VM:~/qt-test/build$ ./qt-test
qt.core.plugin.factoryloader: checking directory path "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms" ...
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqvkkhrdisplay.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqvkkhrdisplay.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vkkhrdisplay"
        ]
    },
    "archlevel": 1,
    "className": "QVkKhrDisplayIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("vkkhrdisplay")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqlinuxfb.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archlevel": 1,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("linuxfb")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqxcb.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqxcb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "xcb"
        ]
    },
    "archlevel": 1,
    "className": "QXcbIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("xcb")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqeglfs.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqeglfs.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "eglfs"
        ]
    },
    "archlevel": 1,
    "className": "QEglFSIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("eglfs")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqvnc.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archlevel": 1,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("vnc")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqoffscreen.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archlevel": 1,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("offscreen")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqwayland-generic.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqwayland-generic.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland"
        ]
    },
    "archlevel": 1,
    "className": "QWaylandIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("wayland")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqminimal.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archlevel": 1,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("minimal")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqwayland-egl.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqwayland-egl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-egl"
        ]
    },
    "archlevel": 1,
    "className": "QWaylandEglPlatformIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("wayland-egl")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqminimalegl.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqminimalegl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimalegl"
        ]
    },
    "archlevel": 1,
    "className": "QMinimalEglIntegrationPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("minimalegl")
qt.core.plugin.factoryloader: checking directory path "/home/michal/qt-test/build/platforms" ...
qt.core.library: "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqxcb.so" loaded library
qt.core.library: "Xcursor" loaded library
qt.core.plugin.factoryloader: checking directory path "/usr/lib/x86_64-linux-gnu/qt6/plugins/platformthemes" ...
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platformthemes/libqgtk3.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platformthemes/libqgtk3.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformThemeFactoryInterface.5.1",
    "MetaData": {
        "Keys": [
            "gtk3"
        ]
    },
    "archlevel": 1,
    "className": "QGtk3ThemePlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("gtk3")
qt.core.plugin.factoryloader: checking directory path "/home/michal/qt-test/build/platformthemes" ...
qt.core.library: "/usr/lib/x86_64-linux-gnu/qt6/plugins/platformthemes/libqgtk3.so" loaded library
qt.core.plugin.factoryloader: checking directory path "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts" ...
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so, metadata=
{
    "IID": "org.qt-project.Qt.QPlatformInputContextFactoryInterface.5.1",
    "MetaData": {
        "Keys": [
            "compose",
            "xim"
        ]
    },
    "archlevel": 1,
    "className": "QComposePlatformInputContextPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("compose", "xim")
qt.core.plugin.factoryloader: looking at "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libibusplatforminputcontextplugin.so"
qt.core.plugin.loader: Found metadata in lib /usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libibusplatforminputcontextplugin.so, metadata=
{
    "IID": "org.qt-project.Qt.QPlatformInputContextFactoryInterface.5.1",
    "MetaData": {
        "Keys": [
            "ibus"
        ]
    },
    "archlevel": 1,
    "className": "QIbusPlatformInputContextPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: Got keys from plugin meta data QList("ibus")
qt.core.plugin.factoryloader: checking directory path "/home/michal/qt-test/build/platforminputcontexts" ...
qt.core.library: "/usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so" loaded library
QQmlApplicationEngine failed to load component
qrc:/qt/qml/qt_test/Main.qml: No such file or directory
qt.core.plugin.factoryloader: checking directory path "/usr/lib/x86_64-linux-gnu/qt6/plugins/accessiblebridge" ...
qt.core.plugin.factoryloader: checking directory path "/home/michal/qt-test/build/accessiblebridge" ...
"/usr/lib/x86_64-linux-gnu/qt6/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so" unloaded library (faked)
"/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/libqxcb.so" unloaded library (faked)
"/usr/lib/x86_64-linux-gnu/qt6/plugins/platformthemes/libqgtk3.so" unloaded library (faked)
"Xcursor" unloaded library (faked)

Project files:
main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    const QUrl url(u"qrc:/qt/qml/qt_test/Main.qml"_qs);
    QObject::connect(
        &engine,
        &QQmlApplicationEngine::objectCreationFailed,
        &app,
        []() { QCoreApplication::exit(-1); },
        Qt::QueuedConnection);
    engine.load(url);

    return app.exec();
}

Main.qml

import QtQuick

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.16)

project(qt-test VERSION 0.1 LANGUAGES CXX)


set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 6.4 REQUIRED COMPONENTS Core Quick Qml)

qt_standard_project_setup(REQUIRES 6.5)

qt_add_executable(qt-test
    main.cpp
)
set_property(TARGET qt-test PROPERTY WIN32_EXECUTABLE true)

qt_add_qml_module(qt-test
    URI qt_test
    VERSION 1.0
    QML_FILES Main.qml
)

target_link_libraries(qt-test
    PRIVATE Qt6::Core Qt6::Quick Qt6::Qml
)

install(TARGETS qt-test
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

I thought I might need to deploy it first so added code below to CMakeLists.txt but I got a cmake error when doing cmake ...

qt_generate_deploy_qml_app_script(
    TARGET qt-test
    OUTPUT_SCRIPT deploy_script
)
install(SCRIPT ${deploy_script})

cmake Error:

...
-- Found WrapOpenGL: TRUE  
-- Could NOT find XKB (missing: XKB_LIBRARY XKB_INCLUDE_DIR) (Required is at least version "0.5.0")
-- Found WrapVulkanHeaders: /usr/include  
CMake Error at /usr/lib/x86_64-linux-gnu/cmake/Qt6Qml/Qt6QmlMacros.cmake:2959 (message):
  Unexpected arguments: OUTPUT_SCRIPT;deploy_script
Call Stack (most recent call first):
  /usr/lib/x86_64-linux-gnu/cmake/Qt6Qml/Qt6QmlMacros.cmake:3104 (qt6_generate_deploy_qml_app_script)
  CMakeLists.txt:32 (qt_generate_deploy_qml_app_script)


-- Configuring incomplete, errors occurred!

Could someone tell me what is wrong?

VRonin

@michal-19937 said in Qt Quick with cmake fails on Linux:

cmake_minimum_required(VERSION 3.16)

from https://doc.qt.io/qt-6/qt-generate-deploy-qml-app-script.html:

Warning: If you are using a CMake version lower than 3.19, make sure that you pass the MANUAL_FINALIZATION option to qt6_add_executable(), and then call qt6_finalize_target() before calling this function

michal.19937

@VRonin I set cmake_minimum_required(VERSION 3.28) and it doesn't change anything.

VRonin

Can you post the full cmake Output?

michal.19937

@VRonin Sure

michal@Mint-VM:~/qt-test/build$ cmake ..
-- The CXX compiler identification is GNU 13.2.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE  
-- Found OpenGL: /usr/lib/x86_64-linux-gnu/libOpenGL.so   
-- Found WrapOpenGL: TRUE  
-- Could NOT find XKB (missing: XKB_LIBRARY XKB_INCLUDE_DIR) (Required is at least version "0.5.0")
-- Found WrapVulkanHeaders: /usr/include  
CMake Error at /usr/lib/x86_64-linux-gnu/cmake/Qt6Qml/Qt6QmlMacros.cmake:2959 (message):
  Unexpected arguments: OUTPUT_SCRIPT;deploy_script
Call Stack (most recent call first):
  /usr/lib/x86_64-linux-gnu/cmake/Qt6Qml/Qt6QmlMacros.cmake:3104 (qt6_generate_deploy_qml_app_script)
  CMakeLists.txt:32 (qt_generate_deploy_qml_app_script)


-- Configuring incomplete, errors occurred!

Full trace: https://drive.google.com/file/d/1R65jCE0caM0J23o6fQU5IC2MN-QALPri/view?usp=sharing

VRonin

I can't replicate, sorry, it works fine in my environment. Do you have something specific in your system or is it a plain Mint?

michal.19937

No, I don't have anything specific. I managed to get it to work on a fresh Mint, I'll install Qt on main Mint the same way I did on the fresh one and see if it works.

michal.19937

Alright, this nightmare finally ended, I got it to work. I believe the issues were caused by missing packages (qt6-declarative-dev and libxcb-cursor0), me forgetting to update CMAKE_PREFIX_PATH after reinstalling Qt and sometimes not removing hidden files from build directory when clearing. It got confusing with more than one problem. Thank you @VRonin for help.
Cheers

shaunrd

I also encountered this message and found very little online, just wanted to share some links for future readers in case it saves them some time. It was quite strange since the documentation for qt_generate_deploy_app_script states This command was introduced in Qt 6.3.. IMHO the version here should be 6.5, since the command was released in preview mode during 6.3 and 6.4 with limited support and a changing interface

It looks like the call to find_package in OPs cmake requests Qt 6.4, and from what I can tell qt_generate_deploy_app_script added support for the OUTPUT_SCRIPT parameter in QtCore 6.5. qt_generate_deploy_app_script was in preview mode during Qt 6.4, and only supported Windows and OSX.

https://doc.qt.io/archives/qt-6.4/qt-generate-deploy-app-script.html

If you're on either of those platforms and want to use Qt 6.4, you might try the FILENAME_VARIABLE instead. I can't speak from experience using this on 6.4 since I'm on Linux. I installed Qt on Ubuntu 24.04 with sudo apt install qt6-base-dev which provided Qt 6.4.2. You can check the Qt version cmake found with the Qt6Core_VERSION variable.

message(STATUS "Found Qt6: ${Qt6Core_VERSION}")

Qt 6.5 however supports Windows / Mac / Linux and the OUTPUT_SCRIPT parameter.

https://doc.qt.io/qt-6.5/qt-generate-deploy-app-script.html