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qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.



  • Hello.
    After last qt5 update I'm getting this message:

    ~ $ qtcreator
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
    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, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
    
    Aborted (core dumped)
    

    Here is strace log https://pastebin.com/1GfBFmUH

    Linux disto is manjaro which is based on archlinux. Any idea what is going on?

    Thank you and best regards.


  • Lifetime Qt Champion

    Hi,

    You should run your application with the QT_DEBUG_PLUGINS environment variable set to 1 to see what might go wrong when the plugin is loaded.



  • ~ $ export QT_DEBUG_PLUGINS=1
    ~ $ qtcreator
    QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/qt/plugins/platforms" ...
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqeglfs.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqeglfs.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "eglfs"
            ]
        },
        "className": "QEglFSIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("eglfs")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqlinuxfb.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqlinuxfb.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "linuxfb"
            ]
        },
        "className": "QLinuxFbIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("linuxfb")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqminimal.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqminimal.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "minimal"
            ]
        },
        "className": "QMinimalIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("minimal")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqminimalegl.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqminimalegl.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "minimalegl"
            ]
        },
        "className": "QMinimalEglIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("minimalegl")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqoffscreen.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqoffscreen.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "offscreen"
            ]
        },
        "className": "QOffscreenIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("offscreen")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqvnc.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqvnc.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "vnc"
            ]
        },
        "className": "QVncIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("vnc")
    QFactoryLoader::QFactoryLoader() looking at "/usr/lib/qt/plugins/platforms/libqxcb.so"
    Found metadata in lib /usr/lib/qt/plugins/platforms/libqxcb.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "xcb"
            ]
        },
        "className": "QXcbIntegrationPlugin",
        "debug": false,
        "version": 330497
    }
    
    
    Got keys from plugin meta data ("xcb")
    QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
    Cannot load library /usr/lib/qt/plugins/platforms/libqxcb.so: (/usr/lib/libxcb-xinerama.so.0: invalid ELF header)
    QLibraryPrivate::loadPlugin failed on "/usr/lib/qt/plugins/platforms/libqxcb.so" : "Cannot load library /usr/lib/qt/plugins/platforms/libqxcb.so: (/usr/lib/libxcb-xinerama.so.0: invalid ELF header)"
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
    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, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
    
    Aborted (core dumped)
    

    So my guess is that this is the key message:

    Got keys from plugin meta data ("xcb")
    QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
    Cannot load library /usr/lib/qt/plugins/platforms/libqxcb.so: (/usr/lib/libxcb-xinerama.so.0: invalid ELF header)
    QLibraryPrivate::loadPlugin failed on "/usr/lib/qt/plugins/platforms/libqxcb.so" : "Cannot load library /usr/lib/qt/plugins/platforms/libqxcb.so: (/usr/lib/libxcb-xinerama.so.0: invalid ELF header)"
    
    /usr/lib/qt/plugins/platforms/libqxcb.so is owned by qt5-base 5.11.1-1
    

    so what now? do I need to reinstall qt5-base or do something else?

    Best regards.


  • Lifetime Qt Champion

    HI,

    Did you run ldd on your libraries and libxcb-xinerama versions ?



  • Hi
    Do you mean something like this?

    ~ $ pacman -Qo /usr/lib/libxcb-xinerama.so.0
    /usr/lib/libxcb-xinerama.so.0 is owned by libxcb 1.13-1
    

    and which file I should run this ldd on exactly?



  • Hi, try: ldd /usr/lib/qt/plugins/platforms/libqxcb.so


  • Lifetime Qt Champion

    You should try installing the corresponding dev packages on your system.



  • The same as before:

    ~ $ ldd /usr/lib/qt/plugins/platforms/libqxcb.so
    /usr/lib/qt/plugins/platforms/libqxcb.so: error while loading shared libraries: /usr/lib/libxcb-xinerama.so.0: invalid ELF header
    

    but after that

    ~ $ sudo pacman -S libxcb
    [sudo] password for tomasz: 
    warning: libxcb-1.13-1 is up to date -- reinstalling
    resolving dependencies...
    looking for conflicting packages...
    
    Packages (1) libxcb-1.13-1
    
    Total Download Size:   0.99 MiB
    Total Installed Size:  3.96 MiB
    Net Upgrade Size:      0.00 MiB
    
    :: Proceed with installation? [Y/n] Y
    :: Retrieving packages...
     libxcb-1.13-1-x86_64          1017.5 KiB   242K/s 00:04 [##############################] 100%
    (1/1) checking keys in keyring                           [##############################] 100%
    (1/1) checking package integrity                         [##############################] 100%
    (1/1) loading package files                              [##############################] 100%
    (1/1) checking for file conflicts                        [##############################] 100%
    (1/1) checking available disk space                      [##############################] 100%
    :: Processing package changes...
    (1/1) reinstalling libxcb                                [##############################] 100%
    :: Running post-transaction hooks...
    (1/1) Arming ConditionNeedsUpdate...
    ~ $ pacman -Qo /usr/lib/libxcb-xinerama.so.0
    /usr/lib/libxcb-xinerama.so.0 is owned by libxcb 1.13-1
    ~ $ ldd /usr/lib/qt/plugins/platforms/libqxcb.so
    	linux-vdso.so.1 (0x00007ffc93f56000)
    	libQt5XcbQpa.so.5 => /usr/lib/libQt5XcbQpa.so.5 (0x00007f730ea63000)
    	libQt5Gui.so.5 => /usr/lib/libQt5Gui.so.5 (0x00007f730e2d5000)
    	libQt5Core.so.5 => /usr/lib/libQt5Core.so.5 (0x00007f730dbd4000)
    	libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007f730d84b000)
    	libc.so.6 => /usr/lib/libc.so.6 (0x00007f730d48f000)
    	libfontconfig.so.1 => /usr/lib/libfontconfig.so.1 (0x00007f730d24c000)
    	libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0x00007f730cf83000)
    	libQt5DBus.so.5 => /usr/lib/libQt5DBus.so.5 (0x00007f730ccf3000)
    	libpthread.so.0 => /usr/lib/libpthread.so.0 (0x00007f730cad5000)
    	libX11-xcb.so.1 => /usr/lib/libX11-xcb.so.1 (0x00007f730c8d3000)
    	libX11.so.6 => /usr/lib/libX11.so.6 (0x00007f730c594000)
    	libXi.so.6 => /usr/lib/libXi.so.6 (0x00007f730c383000)
    	libSM.so.6 => /usr/lib/libSM.so.6 (0x00007f730c17b000)
    	libICE.so.6 => /usr/lib/libICE.so.6 (0x00007f730bf5f000)
    	libXrender.so.1 => /usr/lib/libXrender.so.1 (0x00007f730bd54000)
    	libxcb-xkb.so.1 => /usr/lib/libxcb-xkb.so.1 (0x00007f730bb37000)
    	libxcb-render-util.so.0 => /usr/lib/libxcb-render-util.so.0 (0x00007f730b933000)
    	libxcb-render.so.0 => /usr/lib/libxcb-render.so.0 (0x00007f730b725000)
    	libxcb-sync.so.1 => /usr/lib/libxcb-sync.so.1 (0x00007f730b51e000)
    	libxcb-xfixes.so.0 => /usr/lib/libxcb-xfixes.so.0 (0x00007f730b316000)
    	libxcb-xinerama.so.0 => /usr/lib/libxcb-xinerama.so.0 (0x00007f730b113000)
    	libxcb-randr.so.0 => /usr/lib/libxcb-randr.so.0 (0x00007f730af03000)
    	libxcb-image.so.0 => /usr/lib/libxcb-image.so.0 (0x00007f730acfe000)
    	libxcb-shm.so.0 => /usr/lib/libxcb-shm.so.0 (0x00007f730aafa000)
    	libxcb-keysyms.so.1 => /usr/lib/libxcb-keysyms.so.1 (0x00007f730a8f7000)
    	libxcb-icccm.so.4 => /usr/lib/libxcb-icccm.so.4 (0x00007f730a6f2000)
    	libxcb.so.1 => /usr/lib/libxcb.so.1 (0x00007f730a4c9000)
    	libxcb-shape.so.0 => /usr/lib/libxcb-shape.so.0 (0x00007f730a2c5000)
    	libxkbcommon.so.0 => /usr/lib/libxkbcommon.so.0 (0x00007f730a086000)
    	libxkbcommon-x11.so.0 => /usr/lib/libxkbcommon-x11.so.0 (0x00007f7309e7f000)
    	libm.so.6 => /usr/lib/libm.so.6 (0x00007f7309aea000)
    	libgcc_s.so.1 => /usr/lib/libgcc_s.so.1 (0x00007f73098d2000)
    	libGL.so.1 => /usr/lib/libGL.so.1 (0x00007f7309647000)
    	libpng16.so.16 => /usr/lib/libpng16.so.16 (0x00007f7309411000)
    	libharfbuzz.so.0 => /usr/lib/libharfbuzz.so.0 (0x00007f7309165000)
    	libz.so.1 => /usr/lib/libz.so.1 (0x00007f7308f4e000)
    	libsystemd.so.0 => /usr/lib/libsystemd.so.0 (0x00007f7308cc4000)
    	libicui18n.so.61 => /usr/lib/libicui18n.so.61 (0x00007f7308819000)
    	libicuuc.so.61 => /usr/lib/libicuuc.so.61 (0x00007f730845f000)
    	libpcre2-16.so.0 => /usr/lib/libpcre2-16.so.0 (0x00007f73081e8000)
    	libdouble-conversion.so.1 => /usr/lib/libdouble-conversion.so.1 (0x00007f7307fd8000)
    	libdl.so.2 => /usr/lib/libdl.so.2 (0x00007f7307dd4000)
    	libglib-2.0.so.0 => /usr/lib/libglib-2.0.so.0 (0x00007f7307abd000)
    	/usr/lib64/ld-linux-x86-64.so.2 (0x00007f730efdd000)
    	libexpat.so.1 => /usr/lib/libexpat.so.1 (0x00007f730788b000)
    	libuuid.so.1 => /usr/lib/libuuid.so.1 (0x00007f7307684000)
    	libbz2.so.1.0 => /usr/lib/libbz2.so.1.0 (0x00007f7307474000)
    	libdbus-1.so.3 => /usr/lib/libdbus-1.so.3 (0x00007f7307223000)
    	libXext.so.6 => /usr/lib/libXext.so.6 (0x00007f7307011000)
    	libXau.so.6 => /usr/lib/libXau.so.6 (0x00007f7306e0d000)
    	libXdmcp.so.6 => /usr/lib/libXdmcp.so.6 (0x00007f7306c07000)
    	libxcb-util.so.1 => /usr/lib/libxcb-util.so.1 (0x00007f7306a01000)
    	libGLX.so.0 => /usr/lib/libGLX.so.0 (0x00007f73067d0000)
    	libGLdispatch.so.0 => /usr/lib/libGLdispatch.so.0 (0x00007f730651a000)
    	libgraphite2.so.3 => /usr/lib/libgraphite2.so.3 (0x00007f73062ee000)
    	librt.so.1 => /usr/lib/librt.so.1 (0x00007f73060e6000)
    	liblzma.so.5 => /usr/lib/liblzma.so.5 (0x00007f7305ec0000)
    	liblz4.so.1 => /usr/lib/liblz4.so.1 (0x00007f7305ca3000)
    	libgcrypt.so.20 => /usr/lib/libgcrypt.so.20 (0x00007f7305987000)
    	libicudata.so.61 => /usr/lib/libicudata.so.61 (0x00007f7303de2000)
    	libpcre.so.1 => /usr/lib/libpcre.so.1 (0x00007f7303b70000)
    	libgpg-error.so.0 => /usr/lib/libgpg-error.so.0 (0x00007f7303950000)
    ~ $ qtcreator
    QApplication: invalid style override passed, ignoring it.
    

    so it seems that reinstalling libxcb fixed the issue. So thank you very much guys.
    I own you really big beer :-)

    @SGaist
    there is no such thing on manjaro or archlinux which manjaro is baseed on



  • For those who could face the same issue and didn't solve by reinstalling libxcb: in my case the message was the same but it was caused by apps inside lxc unabling to open display, so, try to run another GUI app like xclock.



  • @DevAlone

    qt.qpa.xcb: could not connect to display <<-- Is that the message you're talking about?

    Could you explain a little better what was your problem and how did you fix it?

    What is lxc? And why to run another GUI app? I really didn't understand what you did to fix this problem.



  • @twar
    Hi, twar!
    I met the same error as yours, and I cannot solve it after using several methods.
    Can you tell me how to fix it more clearly? I'm new to geant4, so I cannot understand what you have said.
    Thank you!

    Best Wishes,
    jcren.



  • Hi
    I faced this problem and I got a new version of linuxdeployqt and now that error is gone.



  • Hi for all!
    I downloaded and extracted XnView MP version 0.96 on Arch Linux and same error happened.
    Képernyőkép_2020-04-16_11-56-17.png

    Solution:
    I am deleted these two files: libfreetype.so and libfreetype.so.6 .
    Képernyőkép_2020-04-16_11-57-29.png

    Képernyőkép_2020-04-16_11-58-14.png

    Here is the result:
    Képernyőkép_2020-04-16_11-59-08.png



  • Hi ,
    I am facing a similar issue could you please help.

    Got keys from plugin meta data ("xcb")
    QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqeglfs.so"
    Got keys from plugin meta data ("eglfs")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqlinuxfb.so"
    Got keys from plugin meta data ("linuxfb")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimal.so"
    Got keys from plugin meta data ("minimal")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimalegl.so"
    Got keys from plugin meta data ("minimalegl")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqoffscreen.so"
    Got keys from plugin meta data ("offscreen")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqvnc.so"
    Got keys from plugin meta data ("vnc")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqxcb.so"
    Got keys from plugin meta data ("xcb")
    loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
    qt.qpa.xcb: could not connect to display
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/opt/appname/libs/Qt/plugins/platforms" even though it was found.
    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, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.


  • Lifetime Qt Champion

    @jarvis said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimalegl.so"
    Got keys from plugin meta data ("minimalegl")
    QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqoffscreen.so"
    Got

    Hi,

    Start your application with the QT_DEBUG_PLUGINS environment variable set to 1 to get more information.



  • I am using Qt-5.15.0, got the same problem.
    More details are:
    QLibraryPrivate::loadPlugin failed on "/opt/Qt/5.15.0/gcc_64/plugins/platforms/libqxcb.so" : "Cannot load library /opt/Qt/5.15.0/gcc_64/plugins/platforms/libqxcb.so: (libxcb-xinerama.so.0: cannot open shared object file: No such file or directory)"

    Solved by installing the dependent package.
    Command to install: sudo apt-get install libxcb-xinerama0



  • Fresh install had the same issues reported here. Did what @Srinivas-Reddy suggested and install libxcb-xinerama0 and everything started working. Thanks!



  • @JamieC I had the same problem, install libxcb-xinerama0 and I solved it, Thanks!



  • Tried reinstalling libxcb and worked for me as well.



  • @Srinivas-Reddy many thanks



  • Thanks very much!
    I spent several hours trying to solve this problem until I got here.
    sudo apt-get install libxcb-xinerama0
    Thanks!



  • @Lengendary Thank you!



  • Hey guys,

    I'm getting the same error but not able to find any reason.
    I'm building this project, https://github.com/BelledonneCommunications/linphone-desktop
    and getting the error,

    (linphone) ➜  Packages git:(master) ./Linphone-4.5.1.AppImage 
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
    This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
    
    Available platform plugins are: xcb.
    
    [1]    28317 abort (core dumped)  ./Linphone-4.5.1.AppImage
    (linphone) ➜  Packages git:(master) ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so                         
    	linux-vdso.so.1 (0x00007ffe12cd8000)
    	libQt5XcbQpa.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x00007f79c2a18000)
    	libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f79c27d3000)
    	libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f79c251f000)
    	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f79c2302000)
    	libQt5Gui.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Gui.so.5 (0x00007f79c1ab3000)
    	libQt5DBus.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5DBus.so.5 (0x00007f79c1827000)
    	libQt5Core.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Core.so.5 (0x00007f79c108c000)
    	libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007f79c0e00000)
    	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f79c0be1000)
    	libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f79c09df000)
    	libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f79c07b7000)
    	libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f79c05ad000)
    	libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f79c039b000)
    	libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f79c0063000)
    	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f79bfcc5000)
    	libxkbcommon-x11.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007f79bfabd000)
    	libxkbcommon.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f79bf87e000)
    	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f79bf67a000)
    	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f79bf2f1000)
    	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f79bf0d9000)
    	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f79bece8000)
    	libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f79beae6000)
    	libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f79be7cf000)
    	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f79be59d000)
    	libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f79be36b000)
    	libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f79be11e000)
    	libicui18n.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicui18n.so.56 (0x00007f79bdc85000)
    	libicuuc.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicuuc.so.56 (0x00007f79bd8cd000)
    	libicudata.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicudata.so.56 (0x00007f79bbeea000)
    	/lib64/ld-linux-x86-64.so.2 (0x00007f79c2fbe000)
    	libGLX.so.0 => /usr/lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f79bbcb9000)
    	libGLdispatch.so.0 => /usr/lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f79bba03000)
    	libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f79bb7ff000)
    	libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f79bb5f9000)
    	libxcb-xkb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007f79bb3dd000)
    	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f79bb16b000)
    	libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f79baee7000)
    	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f79bacd2000)
    	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f79baaca000)
    	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f79ba8a4000)
    	liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f79ba688000)
    	libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f79ba36c000)
    	libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f79ba157000)
    

    What could be the issue? Please suggest.
    Please let me know if you need to know anything else for this.



  • @singhravi said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

    Hey guys,

    I'm getting the same error but not able to find any reason.
    I'm building this project, https://github.com/BelledonneCommunications/linphone-desktop
    and getting the error,

    (linphone) ➜  Packages git:(master) ./Linphone-4.5.1.AppImage 
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
    This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
    
    Available platform plugins are: xcb.
    
    [1]    28317 abort (core dumped)  ./Linphone-4.5.1.AppImage
    (linphone) ➜  Packages git:(master) ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so                         
    	linux-vdso.so.1 (0x00007ffe12cd8000)
    	libQt5XcbQpa.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x00007f79c2a18000)
    	libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f79c27d3000)
    	libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f79c251f000)
    	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f79c2302000)
    	libQt5Gui.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Gui.so.5 (0x00007f79c1ab3000)
    	libQt5DBus.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5DBus.so.5 (0x00007f79c1827000)
    	libQt5Core.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Core.so.5 (0x00007f79c108c000)
    	libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007f79c0e00000)
    	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f79c0be1000)
    	libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f79c09df000)
    	libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f79c07b7000)
    	libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f79c05ad000)
    	libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f79c039b000)
    	libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f79c0063000)
    	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f79bfcc5000)
    	libxkbcommon-x11.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007f79bfabd000)
    	libxkbcommon.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f79bf87e000)
    	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f79bf67a000)
    	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f79bf2f1000)
    	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f79bf0d9000)
    	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f79bece8000)
    	libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f79beae6000)
    	libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f79be7cf000)
    	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f79be59d000)
    	libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f79be36b000)
    	libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f79be11e000)
    	libicui18n.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicui18n.so.56 (0x00007f79bdc85000)
    	libicuuc.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicuuc.so.56 (0x00007f79bd8cd000)
    	libicudata.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicudata.so.56 (0x00007f79bbeea000)
    	/lib64/ld-linux-x86-64.so.2 (0x00007f79c2fbe000)
    	libGLX.so.0 => /usr/lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f79bbcb9000)
    	libGLdispatch.so.0 => /usr/lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f79bba03000)
    	libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f79bb7ff000)
    	libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f79bb5f9000)
    	libxcb-xkb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007f79bb3dd000)
    	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f79bb16b000)
    	libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f79baee7000)
    	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f79bacd2000)
    	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f79baaca000)
    	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f79ba8a4000)
    	liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f79ba688000)
    	libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f79ba36c000)
    	libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f79ba157000)
    

    What could be the issue? Please suggest.
    Please let me know if you need to know anything else for this.

    Hey @SGaist , Can you please suggest anything for this?


  • Lifetime Qt Champion

    @singhravi run ldd on the plugin itself.



  • @SGaist Thanks a lot for the reply!
    Do you mean this? ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so
    If yes, then I've included its output in the original comment.
    Please let me know if this is not what you mean.


  • Lifetime Qt Champion

    I missed that line.

    I see that you have that issue with an AppImage, does it also happen with just your binary ?



  • @SGaist Nope. The created binary works fine.
    Only the packaged Appimage gives this issue.
    PS, sorry for the delay in comments as its blocking me for 600 seconds after a comment. SMH


  • Lifetime Qt Champion

    What are you using to create that AppImage ?



  • @SGaist
    I'm building this project from github, https://github.com/BelledonneCommunications/linphone-desktop.
    It has the everything included in its cmakelists.txt and I just need to add -DENABLE_APP_PACKAGING=YES to create the package.
    It uses linuxdeploy and linuxdeploy-plugin-qt for packaging.
    This is the script for packaging, https://github.com/BelledonneCommunications/linphone-desktop/blob/master/linphone-app/tools/create_appimage.sh



  • @SGaist
    I'm building this project from github, https://github.com/BelledonneCommunications/linphone-desktop.
    It has the everything included in its cmakelists.txt and I just need to add -DENABLE_APP_PACKAGING=YES to create the package.
    It uses linuxdeploy and linuxdeploy-plugin-qt for packaging.
    This is the script for packaging, https://github.com/BelledonneCommunications/linphone-desktop/blob/master/linphone-app/tools/create_appimage.sh

    Hey @SGaist , Please let me know if you need anyother information.



  • One thing I noted while running the Appimage with QT_DEBUG_PLUGINS=1 was that it was trying to load plugins from a directory in tmp directory which does not exists. I don't know if this is the correct behaviour.
    Following the log when i run the Appimage,

    QFactoryLoader::QFactoryLoader() checking directory path "/tmp/.mount_LinphoELXhn2/usr/plugins/platforms" ...
    QFactoryLoader::QFactoryLoader() looking at "/tmp/.mount_LinphoELXhn2/usr/plugins/platforms/libqxcb.so"
    Found metadata in lib /tmp/.mount_LinphoELXhn2/usr/plugins/platforms/libqxcb.so, metadata=
    {
        "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
        "MetaData": {
            "Keys": [
                "xcb"
            ]
        },
        "className": "QXcbIntegrationPlugin",
        "debug": false,
        "version": 329989
    }
    
    
    Got keys from plugin meta data ("xcb")
    QFactoryLoader::QFactoryLoader() checking directory path "/tmp/.mount_LinphoELXhn2/usr/bin/platforms" ...
    Cannot load library /tmp/.mount_LinphoELXhn2/usr/plugins/platforms/libqxcb.so: (/tmp/.mount_LinphoELXhn2/usr/plugins/platforms/../../lib/libQt5XcbQpa.so.5: symbol _ZN11QFontEngine14bitmapForGlyphEj6QFixedRK10QTransform version Qt_5_PRIVATE_API not defined in file libQt5Gui.so.5 with link time reference)
    QLibraryPrivate::loadPlugin failed on "/tmp/.mount_LinphoELXhn2/usr/plugins/platforms/libqxcb.so" : "Cannot load library /tmp/.mount_LinphoELXhn2/usr/plugins/platforms/libqxcb.so: (/tmp/.mount_LinphoELXhn2/usr/plugins/platforms/../../lib/libQt5XcbQpa.so.5: symbol _ZN11QFontEngine14bitmapForGlyphEj6QFixedRK10QTransform version Qt_5_PRIVATE_API not defined in file libQt5Gui.so.5 with link time reference)"
    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
    This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
    
    Available platform plugins are: xcb.
    
    [1]    7814 abort (core dumped)  ./Linphone-4.5.1.AppImage
    


  • Hi, AppImage extracts all the files into the /tmp directory, so it's expected that the files exist there (as long as the app runs).
    But it seems all Qt files are not from version Qt 5.12.9, the error is that libQt5XcbQpa.so.5 is looking for the function QFontEngine::bitmapForGlyph() in libQt5Gui.so.5 but it's not there. I think that function is maybe 6 years old, perhaps you any other (older) Qt version installed than 5.12.9?

    Edit: I greped the sources, the function signature was changed between 5.12.4 and 5.12.5:
    in Qt 5.12.4: QImage QFontEngine::bitmapForGlyph(glyph_t, QFixed subPixelPosition, const QTransform&);

    in Qt 5.12.5: QImage QFontEngine::bitmapForGlyph(glyph_t, QFixed subPixelPosition, const QTransform&, const QColor &);

    since libQt5XcbQpa.so.5 asks for the old one, most likely it's the other way around, i.e. libQt5XcbQpa.so.5 is from 5.12.4 (or older Qt version) and libQt5Gui.so.5 is from 5.12.9.



  • @hskoglund Thanks a lot for the explanation! This is great.
    Actually i've installed Qt 5.12.9 with the installer and all the other dependencies were installed using apt which i think must be causing the mismatch in compatible versions as 18.04 ubuntu could have old packages in its repo.
    So what do you suggest? should i down grade qt version or should i install newer dependency libraries by using some custom apt sources?



  • In the long run the best is to do an apt remove for the apt installed Qt and just stick with Qt’s online installer (because it gives you fresher versiobns).

    But you can also try to harmonize them, open a Terminal and type qtdiag (it should pick up the apt installed Qt)
    Ser what version is says, then use the MaintenanceTool to downgrade to that version.



  • @hskoglund Thanks for the suggestion!
    Actually I did not installed the Qt using apt but all the other dependecies such as qtchooser, etc.
    Maybe that is why when i ran qtdiag, it gave the following output, qtdiag: could not find a Qt installation of ''?
    Please suggest.



  • Hmm, so apt gave you a piecemeal version of Qt, however enough stuff to error out AppImage.

    That older/faulty libQt5XcbQpa.so.5 should be in your /usr/lib/x86_64-linux-gnu anyways, try this in Terminal:

    strings /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 | grep Qt | more
    

    In that list should be some version markers, like Qt_5_PRIVATE_API, Qt_5 and Qt_5.9 or something similar...

    Edit: just realized, there's an easier way to establish the version of that apt-flavored partial Qt installation: just list libQt5XcbQpa in Terminal, like this:

    ls -l /usr/lib/x86_64-linux-gnu/libQt5Xcb*
    

    this should show what version apt gave you...



  • @hskoglund
    Yes, libQt5XcbQpa.so.5 has Qt_5_PRIVATE_API, Qt_5 and Qt_5.9 in it. Please find the whole output below.

    _ZN14QXcbConnection19getQtSelectionOwnerEv
    _ZN9QtPrivate20QStringList_containsEPK11QStringListRK7QStringN2Qt15CaseSensitivityE
    _ZN7QObject10startTimerEiN2Qt9TimerTypeE
    _ZN7QObject7connectEPKS_PKcS1_S3_N2Qt14ConnectionTypeE
    _ZN11QMetaObject12invokeMethodEP7QObjectPKcN2Qt14ConnectionTypeE22QGenericReturnArgument16QGenericArgumentS7_S7_S7_S7_S7_S7_S7_S7_S7_
    _ZN10QByteArrayC1EiN2Qt14InitializationE
    _ZN16QCoreApplication13testAttributeEN2Qt20ApplicationAttributeE
    _ZNK7QString11lastIndexOfE5QChariN2Qt15CaseSensitivityE
    _ZN16QCoreApplication12setAttributeEN2Qt20ApplicationAttributeEb
    _ZN7QStringC1EiN2Qt14InitializationE
    _ZNK20QPlatformIntegration18defaultWindowStateE6QFlagsIN2Qt10WindowTypeEE
    _ZNK11QMetaMethod6invokeEP7QObjectN2Qt14ConnectionTypeE22QGenericReturnArgument16QGenericArgumentS5_S5_S5_S5_S5_S5_S5_S5_S5_
    _ZN9QKeyEventC1EN6QEvent4TypeEi6QFlagsIN2Qt16KeyboardModifierEEjjjRK7QStringbt
    _ZN22QWindowSystemInterface22handleContextMenuEventEP7QWindowbRK6QPointS4_6QFlagsIN2Qt16KeyboardModifierEE
    _ZN22QWindowSystemInterface22handleExtendedKeyEventEP7QWindowmN6QEvent4TypeEi6QFlagsIN2Qt16KeyboardModifierEEjjjRK7QStringbtb
    _ZNK7QString10startsWithE13QLatin1StringN2Qt15CaseSensitivityE
    _ZNK7QString7indexOfE13QLatin1StringiN2Qt15CaseSensitivityE
    _ZNK7QString8splitRefE5QCharNS_13SplitBehaviorEN2Qt15CaseSensitivityE
    _ZN10QBasicDrag12updateCursorEN2Qt10DropActionE
    _ZN15QtSharedPointer20ExternalRefCountData9getAndRefEPK7QObject
    _ZN22QWindowSystemInterface10handleDragEP7QWindowPK9QMimeDataRK6QPoint6QFlagsIN2Qt10DropActionEE
    _ZNK23QPlatformDragQtResponse10answerRectEv
    _ZNK23QPlatformDropQtResponse10isAcceptedEv
    _ZNK23QPlatformDropQtResponse14acceptedActionEv
    _ZN22QWindowSystemInterface10handleDropEP7QWindowPK9QMimeDataRK6QPoint6QFlagsIN2Qt10DropActionEE
    _ZNK13QPlatformDrag13defaultActionE6QFlagsIN2Qt10DropActionEES0_INS1_16KeyboardModifierEE
    _ZN22QWindowSystemInterface29handleScreenOrientationChangeEP7QScreenN2Qt17ScreenOrientationE
    _ZN7QObject18staticQtMetaObjectE
    _ZN15QPlatformScreen24setOrientationUpdateMaskE6QFlagsIN2Qt17ScreenOrientationEE
    _ZN22QWindowSystemInterface21handleWindowActivatedINS_15DefaultDeliveryEEEvP7QWindowN2Qt11FocusReasonE
    _ZN10QXcbWindow19setMotifWindowFlagsE6QFlagsIN2Qt10WindowTypeEE
    _ZN10QXcbWindow16handleMouseEventEjRK6QPointS2_6QFlagsIN2Qt16KeyboardModifierEENS4_16MouseEventSourceE
    _ZN22QWindowSystemInterface16handleMouseEventINS_15DefaultDeliveryEEEvP7QWindowmRK7QPointFS6_6QFlagsIN2Qt11MouseButtonEES7_INS8_16KeyboardModifierEENS8_16MouseEventSourceE
    _ZN10QXcbWindow24handleButtonReleaseEventEiiiii6QFlagsIN2Qt16KeyboardModifierEEjNS1_16MouseEventSourceE
    _ZN10QXcbWindow23handleMotionNotifyEventEiiii6QFlagsIN2Qt16KeyboardModifierEEjNS1_16MouseEventSourceE
    _ZN10QXcbWindow22handleButtonPressEventEiiiii6QFlagsIN2Qt16KeyboardModifierEEjNS1_16MouseEventSourceE
    _ZN22QWindowSystemInterface16handleWheelEventEP7QWindowmRK7QPointFS4_iN2Qt11OrientationE6QFlagsINS5_16KeyboardModifierEE
    _ZN10QXcbWindow18handleXIMouseEventEP14xcb_ge_event_tN2Qt16MouseEventSourceE
    _ZN14QXcbConnection17xiToQtMouseButtonEj
    _ZN10QXcbWindow24setNetWmStateWindowFlagsE6QFlagsIN2Qt10WindowTypeEE
    _ZN10QXcbWindow14setWindowStateEN2Qt11WindowStateE
    _ZThn16_N10QXcbWindow14setWindowStateEN2Qt11WindowStateE
    _ZN10QXcbWindow19doStartSystemResizeERK6QPointN2Qt6CornerE
    _ZN10QXcbWindow17startSystemResizeERK6QPointN2Qt6CornerE
    _ZN14QXcbConnection30startSystemResizeForTouchBeginEjRK6QPointN2Qt6CornerE
    _ZThn16_N10QXcbWindow17startSystemResizeERK6QPointN2Qt6CornerE
    _ZN10QXcbWindow15setWmWindowTypeE6QFlagsIN19QXcbWindowFunctions12WmWindowTypeEES0_IN2Qt10WindowTypeEE
    _ZN22QWindowSystemInterface24handleWindowStateChangedINS_15DefaultDeliveryEEEvP7QWindowN2Qt11WindowStateEi
    _ZN10QXcbWindow14setWindowFlagsE6QFlagsIN2Qt10WindowTypeEE
    _ZThn16_N10QXcbWindow14setWindowFlagsE6QFlagsIN2Qt10WindowTypeEE
    _ZN6QImage23convertToFormat_inplaceENS_6FormatE6QFlagsIN2Qt19ImageConversionFlagEE
    _ZNK6QImage22convertToFormat_helperENS_6FormatE6QFlagsIN2Qt19ImageConversionFlagEE
    _ZN15QPlatformWindow30handleContentOrientationChangeEN2Qt17ScreenOrientationE
    _ZN6QColorC1EN2Qt11GlobalColorE
    _ZN22QGuiApplicationPrivate15getPixmapCursorEN2Qt11CursorShapeE
    _ZNK6QImage15createAlphaMaskE6QFlagsIN2Qt19ImageConversionFlagEE
    _ZN7QPixmap16fromImageInPlaceER6QImage6QFlagsIN2Qt19ImageConversionFlagEE
    _ZN22QWindowSystemInterface16handleWheelEventEP7QWindowmRK7QPointFS4_6QPointS5_6QFlagsIN2Qt16KeyboardModifierEENS7_11ScrollPhaseENS7_16MouseEventSourceEb
    _ZN22QWindowSystemInterface17handleTabletEventEP7QWindowmRK7QPointFS4_ii6QFlagsIN2Qt11MouseButtonEEdiiddixS5_INS6_16KeyboardModifierEE
    _ZN16QLoggingCategory10setEnabledE9QtMsgTypeb
    _ZN22QWindowSystemInterface16handleTouchEventINS_15DefaultDeliveryEEEvP7QWindowmP12QTouchDeviceRK5QListINS_10TouchPointEE6QFlagsIN2Qt16KeyboardModifierEE
    _ZNK7QString7compareERKS_N2Qt15CaseSensitivityE
    _ZN14QFactoryLoaderC1EPKcRK7QStringN2Qt15CaseSensitivityE
    _ZN9QtPrivate16QStringList_joinEPK11QStringListPK5QChari
    _ZN6QBrushC1EN2Qt11GlobalColorENS0_10BrushStyleE
    _ZN6QBrushC1ERK6QColorN2Qt10BrushStyleE
    _ZN9QMetaType25registerConverterFunctionEPKN9QtPrivate25AbstractConverterFunctionEii
    _ZN9QtPrivate28QStringList_removeDuplicatesEP11QStringList
    _ZNK7QString5splitE5QCharNS_13SplitBehaviorEN2Qt15CaseSensitivityE
    _ZN7QObject11connectImplEPKS_PPvS1_S3_PN9QtPrivate15QSlotObjectBaseEN2Qt14ConnectionTypeEPKiPK11QMetaObject
    _ZNK7QString8endsWithE13QLatin1StringN2Qt15CaseSensitivityE
    _ZN6QImage4fillEN2Qt11GlobalColorE
    _ZNK7QString7indexOfE5QChariN2Qt15CaseSensitivityE
    _ZN20QEventDispatcherGlib13registerTimerEiiN2Qt9TimerTypeEP7QObject
    _ZN20QEventDispatcherUNIX13registerTimerEiiN2Qt9TimerTypeEP7QObject
    _ZNK6QImage11transformedERK10QTransformN2Qt18TransformationModeE
    libQt5Gui.so.5
    libQt5DBus.so.5
    libQt5Core.so.5
    libQt5XcbQpa.so.5
    Qt_5_PRIVATE_API
    Qt_5
    Qt_5.9
    Qt: XKEYBOARD extension not present on the X server.
    Qt: Failed to initialize XKB extension
    Qt: Unsupported XKB version (We want %d %d, but X server has %d %d)
    Qt: failed to select notify events from xcb-xkb
    Qt: Couldn't interpret the _XKB_RULES_NAMES property
    Qt: Failed to compile US keymap, shortcut handling with non-Latin keyboard layouts may not be fully functional!
    Qt: failed to retrieve the virtual modifier names from XKB
    Qt: failed to retrieve the virtual modifier map from XKB
    Qt: failed to get modifier mapping
    Qt: failed to retrieve the keyboard mapping from XKB
    Qt: Failed to create XKB context!
    Qt: Could not determine keyboard configuration data from X server, will use hard-coded keymap configuration.
    Qt: Failed to compile a keymap!
    Qt: Failed to create xkb state!
    Qt: couldn't get core keyboard device info
    XInput version %d.%d is available and Qt supports 2.2 or greater
    Qt: Session management error: %s
    org.qt-project.Qt.QPA.Xcb.QXcbGlIntegrationFactoryInterface.5.5
    QtMetaTypePrivate::QSequentialIterableImpl
          <annotation value="QDBusMenuLayoutItem" name="org.qtproject.QtDBus.QtTypeName.Out1"/>
          <annotation value="QList&lt;int&gt;" name="org.qtproject.QtDBus.QtTypeName.In0"/>
          <annotation value="QDBusMenuItemList" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QList&lt;QDBusMenuEvent&gt;" name="org.qtproject.QtDBus.QtTypeName.In0"/>
          <annotation value="QList&lt;int&gt;" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QList&lt;int&gt;" name="org.qtproject.QtDBus.QtTypeName.In0"/>
          <annotation value="QList&lt;int&gt;" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QList&lt;int&gt;" name="org.qtproject.QtDBus.QtTypeName.Out1"/>
          <annotation value="QDBusMenuItemList" name="org.qtproject.QtDBus.QtTypeName.In0"/>
          <annotation value="QDBusMenuItemKeysList" name="org.qtproject.QtDBus.QtTypeName.In1"/>
          <annotation value="QXdgDBusImageVector" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QXdgDBusImageVector" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QXdgDBusImageVector" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QXdgDBusToolTipStruct" name="org.qtproject.QtDBus.QtTypeName"/>
    Note that Qt no longer ships fonts. Deploy some (from http://dejavu-fonts.org for example) or switch to fontconfig.
    QtMetaTypePrivate::QPairVariantInterfaceImpl
    QtMetaTypePrivate::QAssociativeIterableImpl
    WARNING Qt AtSpiAdaptor: Could not find accessible on path: 
    WARNING Qt AtSpiAdaptor: Could not find application interface for: 
    WARNING Qt AtSpiAdaptor: Could not find table interface for: 
    WARNING Qt AtSpiAdaptor: Accessible invalid: 
          <annotation value="QSpiAttributeSet" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAttributeSet" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiRangeList" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAttributeSet" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAttributeSet" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiIntList" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiIntList" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiRect" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiActionArray" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReferenceArray" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiRelationArray" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiUIntList" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAttributeSet" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAccessibleCacheArray" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiAccessibleCacheItem" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiObjectReference" name="org.qtproject.QtDBus.QtTypeName.Out0"/>
          <annotation value="QSpiDeviceEvent" name="org.qtproject.QtDBus.QtTypeName.In0"/>
          <annotation value="QSpiDeviceEvent" name="org.qtproject.QtDBus.QtTypeName.In0"/>
    

    Does that mean that this library is for Qt 5.9? And is not compatible with Qt 5.12.9 that we have installed with Qt installer?

    We're getting the similar results for the ls command,

    -rw-r--r-- 1 root root    1602 Feb  7  2020 /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.prl
    lrwxrwxrwx 1 root root      21 Feb  7  2020 /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so -> libQt5XcbQpa.so.5.9.5
    lrwxrwxrwx 1 root root      21 Feb  7  2020 /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 -> libQt5XcbQpa.so.5.9.5
    lrwxrwxrwx 1 root root      21 Feb  7  2020 /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5.9 -> libQt5XcbQpa.so.5.9.5
    -rw-r--r-- 1 root root 1070840 Feb  7  2020 /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5.9.5
    


  • Indeed, the apt version of Qt you've got is 5.9.5. which does not play well with 5.12.9 :-(

    Easiest short-term solution to get AppImage working is to try downgrade your 5.12.9 to 5.9.5 (with a bit of luck any 5.9.x version will do, but see if you can find 5.9.5 first).

    (Long-term: try purging all apt-flavored Qt stuff from your Ubuntu system and rely solely on Qt's online installer.)



  • @hskoglund Thanks for the confirmation!
    Actually as per the application doc, its required to be 5.12 or greater,
    For Desktop : you will need Qt5 (5.12 or newer). C++11 support is required!

    I've uninstalled qt5-doc and other dependent packages installed via apt and built it again but xcb error is still there.
    I'm checking if there is anything else remained to be removed.
    Will update.


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