Qt 5.8 Installation and Qt Creator launch issue

Manohar_SL

Hi,

Am trying to install Qt5.8 on my Ubuntu14.04 machine. Installation was successful but after that when asked to launch Qt creator i got following error.

This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
Reinstalling the application may fix this problem.

I have installed Qt5.7 and its working fine.
Plz help with solution.

Regards
Manohar

jsulm

@Manohar_SL How exactly did you install Qt 5.8?

Manohar_SL

@jsulm Thanks for the response.

I had downloaded qt-opensource-linux-x64-android-5.8.0.run.
In command promt just gave command ./qt-opensource-linux-x64-android-5.8.0.run
and just followed the steps at the end Launch Qt creator was checked and finish.
But in command promt just got this
This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
Reinstalling the application may fix this problem.

SGaist

Hi,

Do you mean Qt Creator 4.2.1 fails to start on your machine ?

Artmetic

maybe try find the problem using
ldd qtcreator
or
sudo apt-cache search xcb
sudo apt-get install xcb

Manohar_SL

@SGaist yes Qt creator version is 4.2.1
@Artmetic ldd qtcreator command resulted with following

linux-vdso.so.1 =>  (0x00007fffc77fe000)
libExtensionSystem.so.4 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/qtcreator/libExtensionSystem.so.4 (0x00007fa64b823000)
libAggregation.so.4 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/qtcreator/libAggregation.so.4 (0x00007fa64b61c000)
libUtils.so.4 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/qtcreator/libUtils.so.4 (0x00007fa64b24f000)
libQt5Widgets.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/Qt/lib/libQt5Widgets.so.5 (0x00007fa64aa1e000)
libQt5Gui.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/Qt/lib/libQt5Gui.so.5 (0x00007fa64a282000)
libQt5Concurrent.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/Qt/lib/libQt5Concurrent.so.5 (0x00007fa64a07b000)
libQt5Network.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/Qt/lib/libQt5Network.so.5 (0x00007fa649cf5000)
libQt5Core.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/Qt/lib/libQt5Core.so.5 (0x00007fa6495d4000)
libGL.so.1 => /usr/lib/x86_64-linux-gnu/mesa/libGL.so.1 (0x00007fa649350000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa649132000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fa648e2d000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fa648b27000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa648911000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa64854a000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa648346000)
libQt5Qml.so.5 => /home/manu/Qt5.8.0/Tools/QtCreator/bin/./../lib/qtcreator/../Qt/lib/libQt5Qml.so.5 (0x00007fa647d4a000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fa647b31000)
libicui18n.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicui18n.so.56 (0x00007fa647696000)
libicuuc.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicuuc.so.56 (0x00007fa6472de000)
libicudata.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicudata.so.56 (0x00007fa6458fb000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fa6456f2000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fa6454f0000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fa6451e8000)
/lib64/ld-linux-x86-64.so.2 (0x00007fa64ba69000)
libglapi.so.0 => /usr/lib/x86_64-linux-gnu/libglapi.so.0 (0x00007fa644fc0000)
libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007fa644dae000)
libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007fa644bab000)
libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007fa6449a4000)
libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007fa6447a2000)
libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fa64446d000)
libxcb-glx.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-glx.so.0 (0x00007fa644255000)
libxcb-dri2.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri2.so.0 (0x00007fa644050000)
libxcb-dri3.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri3.so.0 (0x00007fa643e4d000)
libxcb-present.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-present.so.0 (0x00007fa643c49000)
libxcb-sync.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007fa643a43000)
libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fa643824000)
libxshmfence.so.1 => /usr/lib/x86_64-linux-gnu/libxshmfence.so.1 (0x00007fa643621000)
libXxf86vm.so.1 => /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1 (0x00007fa64341b000)
libdrm.so.2 => /usr/lib/x86_64-linux-gnu/libdrm.so.2 (0x00007fa64320d000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fa642fce000)
libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fa642dc9000)
libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fa642bc3000)

jsulm

@Manohar_SL What does

ldd qt/5.8/gcc_64/plugins/platforms/libqxcb.so

say?

Manohar_SL

@jsulm following was the result

/home/manu/Qt5.8.0/5.8/gcc_64/plugins/platforms/libqxcb.so: /opt/Qt5.7.0/5.7/gcc_64/lib/libQt5Core.so.5: version `Qt_5.8' not found (required by /home/manu/Qt5.8.0/5.8/gcc_64/plugins/platforms/libqxcb.so)
linux-vdso.so.1 => (0x00007fffa8066000)
libQt5XcbQpa.so.5 => /opt/Qt5.7.0/5.7/gcc_64/lib/libQt5XcbQpa.so.5 (0x00007f49952de000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f49950bc000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f4994db4000)
libQt5Gui.so.5 => /opt/Qt5.7.0/5.7/gcc_64/lib/libQt5Gui.so.5 (0x00007f499460c000)
libQt5DBus.so.5 => /opt/Qt5.7.0/5.7/gcc_64/lib/libQt5DBus.so.5 (0x00007f499438b000)
libQt5Core.so.5 => /opt/Qt5.7.0/5.7/gcc_64/lib/libQt5Core.so.5 (0x00007f4993c6f000)
libGL.so.1 => /usr/lib/x86_64-linux-gnu/mesa/libGL.so.1 (0x00007f4993a0a000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f49937ec000)
libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f49934b6000)
libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f49932b4000)
libXi.so.6 => /usr/lib/x86_64-linux-gnu/libXi.so.6 (0x00007f49930a4000)
libSM.so.6 => /usr/lib/x86_64-linux-gnu/libSM.so.6 (0x00007f4992e9b000)
libICE.so.6 => /usr/lib/x86_64-linux-gnu/libICE.so.6 (0x00007f4992c7f000)
libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f4992a60000)
libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f4992823000)
libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f4992580000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f499227c000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f4991f75000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f4991d5f000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4991999000)
libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f4991753000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f499154f000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f4991347000)
libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f499113c000)
libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f4990f2a000)
libEGL.so.1 => /usr/lib/x86_64-linux-gnu/mesa-egl/libEGL.so.1 (0x00007f4990d05000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f4990ac6000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f49908ad000)
libicui18n.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicui18n.so.56 (0x00007f4990412000)
libicuuc.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicuuc.so.56 (0x00007f499005a000)
libicudata.so.56 => /opt/Qt5.7.0/5.7/gcc_64/lib/libicudata.so.56 (0x00007f498e677000)
/lib64/ld-linux-x86-64.so.2 (0x00007f4995831000)
libglapi.so.0 => /usr/lib/x86_64-linux-gnu/libglapi.so.0 (0x00007f498e44f000)
libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007f498e24c000)
libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007f498e046000)
libxcb-glx.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-glx.so.0 (0x00007f498de2e000)
libxcb-dri2.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri2.so.0 (0x00007f498dc29000)
libxcb-dri3.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri3.so.0 (0x00007f498da26000)
libxcb-present.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-present.so.0 (0x00007f498d822000)
libxcb-sync.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007f498d61c000)
libxshmfence.so.1 => /usr/lib/x86_64-linux-gnu/libxshmfence.so.1 (0x00007f498d41a000)
libXxf86vm.so.1 => /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1 (0x00007f498d213000)
libdrm.so.2 => /usr/lib/x86_64-linux-gnu/libdrm.so.2 (0x00007f498d005000)
libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f498cdff000)
libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f498cbfb000)
libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f498c9f5000)
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f498c7ca000)
libpng12.so.0 => /lib/x86_64-linux-gnu/libpng12.so.0 (0x00007f498c5a4000)
libxcb-xfixes.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-xfixes.so.0 (0x00007f498c39c000)
libwayland-client.so.0 => /usr/lib/x86_64-linux-gnu/libwayland-client.so.0 (0x00007f498c18f000)
libwayland-server.so.0 => /usr/lib/x86_64-linux-gnu/libwayland-server.so.0 (0x00007f498bf7e000)
libgbm.so.1 => /usr/lib/x86_64-linux-gnu/libgbm.so.1 (0x00007f498bd75000)
libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f498bb6d000)

SGaist

What do you get if you start Qt Creator from the command line with the QT_DEBUG_PLUGINS environment variable set to 1 ?

Manohar_SL

@SGaist got following result.

QFactoryLoader::QFactoryLoader() checking directory path "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqeglfs.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqeglfs.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"eglfs"
]
},
"className": "QEglFSIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqlinuxfb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"linuxfb"
]
},
"className": "QLinuxFbIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimal.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimal.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimal"
]
},
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimalegl.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimalegl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimalegl"
]
},
"className": "QMinimalEglIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqoffscreen.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqoffscreen.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"offscreen"
]
},
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqvnc.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqvnc.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"vnc"
]
},
"className": "QVncIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so"
Found metadata in lib /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 329728
}

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/manu/Qt5.8.0/Tools/QtCreator/bin/platforms" ...
Cannot load library /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so: (/opt/Qt5.7.0/5.7/gcc_64/lib/libQt5XcbQpa.so.5: symbol _ZNK14QPlatformTheme14fileIconPixmapERK9QFileInfoRK6QSizeF6QFlagsINS_10IconOptionEE, version Qt_5 not defined in file libQt5Gui.so.5 with link time reference)
QLibraryPrivate::loadPlugin failed on "/home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so" : "Cannot load library /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so: (/opt/Qt5.7.0/5.7/gcc_64/lib/libQt5XcbQpa.so.5: symbol _ZNK14QPlatformTheme14fileIconPixmapERK9QFileInfoRK6QSizeF6QFlagsINS_10IconOptionEE, version Qt_5 not defined in file libQt5Gui.so.5 with link time reference)"
This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Reinstalling the application may fix this problem.
Aborted (core dumped)

jsulm

@Manohar_SL Is it possible that you added your Qt 5.7 installation to PATH? Because, as you can see, the system tries to load Qt 5.7 libraries instead of 5.8:
Cannot load library /home/manu/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so: (/opt/Qt5.7.0/5.7/gcc_64/lib/libQt5XcbQpa.so.5: symbol

Manohar_SL

@jsulm Any specific path do i need to set??
Even after setting Qt5.8 lib path to LD_LIBRARY_PATH it fails.

jsulm

@Manohar_SL No, my question was: did you add the path to Qt 5.7 to PATH (you should not do this)? The strange thing is that libqxcb.so seems to depend on libQt5XcbQpa.so.5 from your Qt 5.7. Something is messed up in your setup.

LionTeFromGuernsey

Sadly I regard this as a LOUD IGNORED BUG by QT developers and a THE WORST ERROR MESSAGE TEXT THAT THERE EVER WAS INVENTED!
I have the same problem building Qt-Creator in APRIL 2021 here. Same last year trying to build QtCreator.

~/Qt $ 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.

^C
[1]+  Aborted                 qtcreator/bin/qtcreator
 ~/Qt $ sudo apt-get install xcb  # DOES NOT SOLVE THE PROBLEM!

and it is symptomatic of Qt staff ignoring straight up terrible bugs in comparability alignment - something that should be AUTOMATIC!

Qt company loses at least 70% of business through configuration version and licence incomparability issues.
It is defiantly worth abandoning QT! YES THAT BAD! GOT THE MESSAGE, AND DO NOT HIDE THE TRUTH?

Configuration synchronisation with QT libraries is worse for developers and less bad for installing applications.
The license greed is also JUST NOT WORTH IT! Each release they hijack even more of other users code and call it thier own code! NOT COOL!

JKSH

@LionTeFromGuernsey said in Qt 5.8 Installation and Qt Creator launch issue:

~/Qt $ sudo apt-get install xcb # DOES NOT SOLVE THE PROBLEM!

That does not solve the problem because XCB is not missing

You need to find out which dependencies are missing. Run ldd on plugins/platforms/libqxcb.so and install the libraries that are marked "not found".