qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/"

Qjay · wrote on 15 Apr 2024, 17:15

Hello trying to build and run an application in Qt creator. I have built qt5.15.13 from source and installed qtcreator using installer. I am getting following error , the plugin flag=1 already.

22:41:31: Starting /home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/ETheme...
QML debugging is enabled. Only use this in a safe environment.
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqeglfs.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqeglfs.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "eglfs"
        ]
    },
    "archreq": 0,
    "className": "QEglFSIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archreq": 0,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqminimalegl.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqminimalegl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimalegl"
        ]
    },
    "archreq": 0,
    "className": "QMinimalEglIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqvnc.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archreq": 0,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-egl.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-egl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-egl"
        ]
    },
    "archreq": 0,
    "className": "QWaylandEglPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-egl")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-generic.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-generic.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland"
        ]
    },
    "archreq": 0,
    "className": "QWaylandIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-xcomposite-egl.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-xcomposite-egl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-xcomposite-egl"
        ]
    },
    "archreq": 0,
    "className": "QWaylandXCompositeEglPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-xcomposite-egl")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-xcomposite-glx.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqwayland-xcomposite-glx.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-xcomposite-glx"
        ]
    },
    "archreq": 0,
    "className": "QWaylandXCompositeGlxPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-xcomposite-glx")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
Found metadata in lib /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "xcb"
        ]
    },
    "archreq": 0,
    "className": "QXcbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/Qt-5.15.13/plugins" ...
QFactoryLoader::QFactoryLoader() checking directory path "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug" ...
QFactoryLoader::QFactoryLoader() looking at "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/ETheme"
"Failed to extract plugin meta data from '/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/ETheme'" 
         not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/main.o"
"Failed to extract plugin meta data from '/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/main.o'" 
         not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/Makefile"
QElfParser: '/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/Makefile' is not an ELF object
"'/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/Makefile' is not an ELF object" 
         not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/qrc_qml.cpp"
QElfParser: '/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/qrc_qml.cpp' is not an ELF object
"'/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/qrc_qml.cpp' is not an ELF object" 
         not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/qrc_qml.o"
"Failed to extract plugin meta data from '/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/qrc_qml.o'" 
         not a plugin
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/platforms" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/Qt-5.15.13/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/local/Qt-5.15.13/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/local/Qt-5.15.13/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archreq": 0,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/Qt-5.15.13/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/local/Qt-5.15.13/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/Qt-5.15.13/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/local/Qt-5.15.13/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/Qt-5.15.13/plugins/platforms/libqvnc.so"
Found metadata in lib /usr/local/Qt-5.15.13/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archreq": 0,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/Qt-5.15.13/plugins/platforms/libqwebgl.so"
Found metadata in lib /usr/local/Qt-5.15.13/plugins/platforms/libqwebgl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() checking directory path "/home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/platforms" ...
Cannot load library /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so: (/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5: undefined symbol: _ZN23QPlatformVulkanInstance22presentAboutToBeQueuedEP7QWindow, version Qt_5_PRIVATE_API)
QLibraryPrivate::loadPlugin failed on "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so" : "Cannot load library /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so: (/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5: undefined symbol: _ZN23QPlatformVulkanInstance22presentAboutToBeQueuedEP7QWindow, version Qt_5_PRIVATE_API)"
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/"
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), linuxfb (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), minimal (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), minimalegl (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), offscreen (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), vnc (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), wayland-egl (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), wayland (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), wayland-xcomposite-egl (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), wayland-xcomposite-glx (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), xcb (from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/), linuxfb, minimal, offscreen, vnc, webgl.

22:41:32: /home/nightmare/Projects/qt_projects/E-Scooty-Dashboard-/build/qt5_15-Debug/ETheme crashed.

when i do which libqxcb.so

/home/nightmare/.local/lib/python3.6/site-packages/PySide2/Qt/plugins/platforms/libqxcb.so
/home/nightmare/Qt/QtCreator/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so
/home/nightmare/pyqt_learn/projects/venv/lib/python3.10/site-packages/PyQt6/Qt6/plugins/platforms/libqxcb.so
/snap/mame/4278/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so
/snap/retroarch/2648/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so

thanks

SGaist · 16 Apr 2024, 01:21

Hi,

You seem to have quite a lot of stuff there.

Do you have LD_LIBRARY_PATH modified ?

Are you using the Qt version from your distribution or a different one that you built yourself ?

Qjay · S SGaist 15 Apr 2024, 18:45

@SGaist Hi o/
I am using qt-everywhere from official website : https://download.qt.io/archive/qt/5.15/5.15.13/single/
built on ubuntu 22.04 when I used "./configure" i got following too

Note: The following modules are not being compiled in this configuration:
    webenginecore
    webengine
    webenginewidgets
    pdf
    pdfwidgets

WARNING: QDoc will not be compiled, probably because libclang could not be located. This means that you cannot build the Qt documentation.

Either ensure that llvm-config is in your PATH environment variable, or set LLVM_INSTALL_DIR to the location of your llvm installation.
On Linux systems, you may be able to install libclang by installing the libclang-dev or libclang-devel package, depending on your distribution.
On macOS, you can use Homebrew's llvm package.
On Windows, you must set LLVM_INSTALL_DIR to the installation path.

WARNING: Tool bison is required to build QtWebEngine.

WARNING: Tool bison is required to build QtPdf.

WARNING: QtWebEngine will not be built.

WARNING: QtPdf will not be built.

Qt is now configured for building. Just run 'gmake'.
Once everything is built, you must run 'gmake install'.
Qt will be installed into '/usr/local/Qt-5.15.13'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

I don't think this is affecting my issue anyway. I am only using these additional environment variables in QtCreator

QT_QPA_PLATFORM_PLUGIN_PATH=/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/
QT_DEBUG_PLUGINS=1

now regarding LD_LIBRARY_PATH , I don't think I have set it anywhere or modified it. It's not set in my .bashrc or .profile atleast

thanks :)

hskoglund · wrote on 16 Apr 2024, 06:02

Hi, looks like you have two versions of Qt5 installed:
the default Qt5 one (from the Ubuntu 22.04 distribution
Qt 5.15.3 downloaded from Qt

You're running an app using 5.15.3 but because you've set QT_QPA_PLATFORM_PLUGIN_PATH to the default Qt version which I think lacks support for OpenGl, which is way to xcb plugin from the default Qt fails to load.

Try either removing that QT_QPA_PLATFORM_PLUGIN_PATH env setting, or upgrade the default Qt so that it supports OpenGL (as the 5.15.3 version does) say something like this:
sudo apt remove qt5-default-dev
sudo apt install libqt5opengl5-dev

fchen0000 · wrote on 17 Sept 2024, 04:30

Thanks for the hint, I did sudo apt remove qt5* libqt5* and that solved my problem. The system QT5 was too old.