qt.qpa.plugin: could not find the Qt platform plugin "xcb" in ""
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./analogclock -platform xcb QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qt5.15/plugins/platforms" ... QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5.15/plugins/platforms/libqeglfs.so" Found metadata in lib /usr/local/qt5.15/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/local/qt5.15/plugins/platforms/libqlinuxfb.so" Found metadata in lib /usr/local/qt5.15/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/qt5.15/plugins/platforms/libqminimal.so" Found metadata in lib /usr/local/qt5.15/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/qt5.15/plugins/platforms/libqminimalegl.so" Found metadata in lib /usr/local/qt5.15/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/local/qt5.15/plugins/platforms/libqoffscreen.so" Found metadata in lib /usr/local/qt5.15/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/qt5.15/plugins/platforms/libqvnc.so" Found metadata in lib /usr/local/qt5.15/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/qt5.15/plugins/platforms/libqwebgl.so" Found metadata in lib /usr/local/qt5.15/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/pi/home/pi/platforms" ... qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in "" 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, webgl../analogclock -platform xcb
When I run this command, I get this message:@IknowQT
There are many possibilities if you Google for e.g.
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""So far as I can see you do not have any
xcbplugin library installed at all. You should have a file/usr/local/qt5.15/plugins/platforms/libqxcb.so, but I do not think you even have that? In which case, how did you install what? I am not an expert, but if it is supposed to come from yourXCB Xlib ............................. yesline I don't think it has been installed on your RPi? -
@IknowQT
There are many possibilities if you Google for e.g.
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""So far as I can see you do not have any
xcbplugin library installed at all. You should have a file/usr/local/qt5.15/plugins/platforms/libqxcb.so, but I do not think you even have that? In which case, how did you install what? I am not an expert, but if it is supposed to come from yourXCB Xlib ............................. yesline I don't think it has been installed on your RPi? -
Should the libqxcb.so file be in the path you said? As you said I don't have that file.
Now that I know the cause, is there a way to fix it?
@IknowQT said in qt.qpa.plugin: could not find the Qt platform plugin "xcb" in "":
Should the libqxcb.so file be in the path you said? As you said I don't have that file.
I believe so. Look at the other paths in the diagnostic output.
Now that I know the cause, is there a way to fix it?
Somehow by installing that file, plus any dependencies. Not my area, someone else may know. But how/what did you do to install these library files on your RPi? Did you look through some of the Google hits to see if any apply to your case?
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@IknowQT said in qt.qpa.plugin: could not find the Qt platform plugin "xcb" in "":
Should the libqxcb.so file be in the path you said? As you said I don't have that file.
I believe so. Look at the other paths in the diagnostic output.
Now that I know the cause, is there a way to fix it?
Somehow by installing that file, plus any dependencies. Not my area, someone else may know. But how/what did you do to install these library files on your RPi? Did you look through some of the Google hits to see if any apply to your case?
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I was looking. Most recommended apt install libxcb-xinerama, but I am already up to date and the result is the same
@IknowQT
I think that is the other way round: I believelibxcb-xineramais a library needed for the xcb library, and you have not got that far. Don't you need something likeapt install libxcb # or apt install libqxcbPress the Tab key (possibly twice) at the end of these lines and the shell should show you names of whatever packages match the prefixes.
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@IknowQT
I think that is the other way round: I believelibxcb-xineramais a library needed for the xcb library, and you have not got that far. Don't you need something likeapt install libxcb # or apt install libqxcbPress the Tab key (possibly twice) at the end of these lines and the shell should show you names of whatever packages match the prefixes.
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@IknowQT
Are you compiling and deploying all on RPi, or are you cross-compiling for RPi from another host?
What about tryingfind / -name libqxcb.so -ls 2>/dev/nullon your RPi, and also on host platform if you are cross-compiling?
What about perhaps https://forum.qt.io/topic/125582/qt-5-15-2-do-not-build-libqxcb-so-but-at-the-same-time-qt-5-14-0-successfully-build-libqxcb-so :
Seems like I fix the problem:
sudo apt-get install libxcb-util-devIt required for build Qt 5.15.x but not required for Qt 5.14.x
?
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@IknowQT
Are you compiling and deploying all on RPi, or are you cross-compiling for RPi from another host?
What about tryingfind / -name libqxcb.so -ls 2>/dev/nullon your RPi, and also on host platform if you are cross-compiling?
What about perhaps https://forum.qt.io/topic/125582/qt-5-15-2-do-not-build-libqxcb-so-but-at-the-same-time-qt-5-14-0-successfully-build-libqxcb-so :
Seems like I fix the problem:
sudo apt-get install libxcb-util-devIt required for build Qt 5.15.x but not required for Qt 5.14.x
?
I have built a cross-compilation environment in Ubuntu and am running it by uploading it to Raspberry Pi.
find / -name libqxcb.so -ls 2>/dev/null
Here is the result I tried.
devqt@devqt-desktop:/$ find / -name libqxcb.so -ls 2>/dev/null 29906776 12 -rwxrwxrwx 1 root root 9680 9월 28 2020 /root/rpi-qt_32/sysroot/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so 29127237 12 -rwxrwxrwx 1 root root 9680 9월 28 2020 /root/rpi-qt_32/sysroot/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.sosudo apt-get install libxcb-util-dev
It says package not found.
insteadsudo apt-get install libxcb-util0-dev
sudo apt-get install libxcb-util0There are two packages, so I installed both, but it says that they are already installed.
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I have built a cross-compilation environment in Ubuntu and am running it by uploading it to Raspberry Pi.
find / -name libqxcb.so -ls 2>/dev/null
Here is the result I tried.
devqt@devqt-desktop:/$ find / -name libqxcb.so -ls 2>/dev/null 29906776 12 -rwxrwxrwx 1 root root 9680 9월 28 2020 /root/rpi-qt_32/sysroot/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so 29127237 12 -rwxrwxrwx 1 root root 9680 9월 28 2020 /root/rpi-qt_32/sysroot/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.sosudo apt-get install libxcb-util-dev
It says package not found.
insteadsudo apt-get install libxcb-util0-dev
sudo apt-get install libxcb-util0There are two packages, so I installed both, but it says that they are already installed.
@IknowQT
These look possibly like the required files. Since I know nothing about RPi or cross-compiling for it, I do not know whether these are situated on the cross-compiling machine or on the RPI target. I would guess the compiling machine, but don't know.- If they are on the compiling machine don't they need copying to the RPi?
- If they are on the RPi then where are they, aren't they supposed to be in
/usr/local/qt5.15/plugins/platformsor somewhere Qt plugins are sought?
I know nothing about "after depoly from qtcreator to Raspberry Pi", check whatever instructions you are using?
Earlier:
sudo apt-get install libxcb-util0-dev
sudo apt-get install libxcb-util0and you said "It says the package you said could not be found."
If these worked did you really follow my instruction:
apt install libxcb # or apt install libqxcbPress the Tab key (possibly twice) at the end of these lines and the shell should show you names of whatever packages match the prefixes
or did you just ignore what I said about the Tab key?
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/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.soThe Raspberry Pi also has this file.
it's too hard -
@IknowQT said in qt.qpa.plugin: could not find the Qt platform plugin "xcb" in "":
it's too hard
Best of luck.
I had the same or similar issue.
libqxcb was not present in (install_dir is the path provided with -prefix during configuration)install_dir/plugins/platformsI had to install the recommended packages from https://doc.qt.io/qt-6/linux-requirements.html and then rebuild qt from source(configure, compile, install, copy to target).
Additionally my copy command did not copy libqxcb, so I used compressed version for copying.
In the end I was missing some libs on the target, machine. After this, it worked.
May it be helpful for some future visitor. -
S SGaist has marked this topic as solved on
