Could not load the Qt platform plugin "xcb" in "" problem.
Solved
General and Desktop
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Hi.
I'm trying to configure a cross-compilator for Raspberry Pi 4. I made it working once with Qt 5.12.6 but recently I needed to update it to Qt 5.15 so I followed the steps from here: https://github.com/UvinduW/Cross-Compiling-Qt-for-Raspberry-Pi-4.
When trying to run the example app "qopenglwidget" (step 6), I get error:qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found. Failed to move cursor on screen DSI1: -13 Segmentation faultI tried
sudo apt install libxcb-xinerama0, cause it solved the problem for some but it didn't change anything. I already updated Qt from 5.12.6 to 5.15 on another raspberry following the same tutorial and everything is working fine there so no clue why it doesn't work this time.Thanks.
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@Piotrrr
run ldd on QTDIR/plugins/platforms/libqxcb.so
and install the packages of all missing dependencies. -
Thanks for the reply.
Output ofldd /usr/local/qt5.15/plugins/platforms/libqxcb.so:linux-vdso.so.1 (0xbee48000) /usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0xb6f99000) libQt5XcbQpa.so.5 => /usr/local/qt5.15/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0xb6e97000) libfontconfig.so.1 => /usr/lib/arm-linux-gnueabihf/libfontconfig.so.1 (0xb6e2f000) libfreetype.so.6 => /usr/lib/arm-linux-gnueabihf/libfreetype.so.6 (0xb6d8c000) libz.so.1 => /lib/arm-linux-gnueabihf/libz.so.1 (0xb6d61000) libQt5Gui.so.5 => /usr/local/qt5.15/plugins/platforms/../../lib/libQt5Gui.so.5 (0xb68bc000) libQt5DBus.so.5 => /usr/local/qt5.15/plugins/platforms/../../lib/libQt5DBus.so.5 (0xb684a000) libQt5Core.so.5 => /usr/local/qt5.15/plugins/platforms/../../lib/libQt5Core.so.5 (0xb640f000) libGLESv2.so.2 => /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2 (0xb63f0000) libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb63c6000) libX11-xcb.so.1 => /usr/lib/arm-linux-gnueabihf/libX11-xcb.so.1 (0xb63b4000) libxcb-icccm.so.4 => /usr/lib/arm-linux-gnueabihf/libxcb-icccm.so.4 (0xb63a0000) libxcb-image.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-image.so.0 (0xb638c000) libxcb-shm.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-shm.so.0 (0xb6379000) libxcb-keysyms.so.1 => /usr/lib/arm-linux-gnueabihf/libxcb-keysyms.so.1 (0xb6366000) libxcb-randr.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-randr.so.0 (0xb6349000) libxcb-render-util.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-render-util.so.0 (0xb6335000) libxcb-render.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-render.so.0 (0xb631a000) libxcb-shape.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-shape.so.0 (0xb6307000) libxcb-sync.so.1 => /usr/lib/arm-linux-gnueabihf/libxcb-sync.so.1 (0xb62f1000) libxcb-xfixes.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-xfixes.so.0 (0xb62da000) libxcb-xinerama.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-xinerama.so.0 (0xb62c7000) libxcb-xkb.so.1 => /usr/lib/arm-linux-gnueabihf/libxcb-xkb.so.1 (0xb62a2000) libxcb-xinput.so.0 => not found libxcb.so.1 => /usr/lib/arm-linux-gnueabihf/libxcb.so.1 (0xb6273000) libXext.so.6 => /usr/lib/arm-linux-gnueabihf/libXext.so.6 (0xb6254000) libX11.so.6 => /usr/lib/arm-linux-gnueabihf/libX11.so.6 (0xb6132000) libxkbcommon.so.0 => /usr/lib/arm-linux-gnueabihf/libxkbcommon.so.0 (0xb60e9000) libxkbcommon-x11.so.0 => /usr/lib/arm-linux-gnueabihf/libxkbcommon-x11.so.0 (0xb60d2000) libdl.so.2 => /lib/arm-linux-gnueabihf/libdl.so.2 (0xb60bf000) libstdc++.so.6 => /usr/lib/arm-linux-gnueabihf/libstdc++.so.6 (0xb5f78000) libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0xb5ef6000) libgcc_s.so.1 => /lib/arm-linux-gnueabihf/libgcc_s.so.1 (0xb5ec9000) libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb5d7b000) libxcb-xinput.so.0 => not found libgthread-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgthread-2.0.so.0 (0xb5d69000) libglib-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libglib-2.0.so.0 (0xb5c59000) libexpat.so.1 => /lib/arm-linux-gnueabihf/libexpat.so.1 (0xb5c18000) libuuid.so.1 => /lib/arm-linux-gnueabihf/libuuid.so.1 (0xb5c01000) /lib/ld-linux-armhf.so.3 (0xb6fc1000) libpng16.so.16 => /usr/lib/arm-linux-gnueabihf/libpng16.so.16 (0xb5bc5000) libharfbuzz.so.0 => /usr/lib/arm-linux-gnueabihf/libharfbuzz.so.0 (0xb5ac7000) libdbus-1.so.3 => /lib/arm-linux-gnueabihf/libdbus-1.so.3 (0xb5a76000) libdouble-conversion.so.1 => /usr/lib/arm-linux-gnueabihf/libdouble-conversion.so.1 (0xb5a52000) libicui18n.so.63 => /usr/lib/arm-linux-gnueabihf/libicui18n.so.63 (0xb5804000) libicuuc.so.63 => /usr/lib/arm-linux-gnueabihf/libicuuc.so.63 (0xb567e000) libicudata.so.63 => /usr/lib/arm-linux-gnueabihf/libicudata.so.63 (0xb3c80000) libpcre2-16.so.0 => /usr/lib/arm-linux-gnueabihf/libpcre2-16.so.0 (0xb3c04000) libGLdispatch.so.0 => /usr/lib/arm-linux-gnueabihf/libGLdispatch.so.0 (0xb3b85000) libxcb-util.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-util.so.0 (0xb3b70000) libXau.so.6 => /usr/lib/arm-linux-gnueabihf/libXau.so.6 (0xb3b5d000) libXdmcp.so.6 => /usr/lib/arm-linux-gnueabihf/libXdmcp.so.6 (0xb3b48000) libpcre.so.3 => /lib/arm-linux-gnueabihf/libpcre.so.3 (0xb3ad1000) libgraphite2.so.3 => /usr/lib/arm-linux-gnueabihf/libgraphite2.so.3 (0xb3aa0000) libsystemd.so.0 => /lib/arm-linux-gnueabihf/libsystemd.so.0 (0xb3a03000) libbsd.so.0 => /usr/lib/arm-linux-gnueabihf/libbsd.so.0 (0xb39db000) librt.so.1 => /lib/arm-linux-gnueabihf/librt.so.1 (0xb39c4000) liblzma.so.5 => /lib/arm-linux-gnueabihf/liblzma.so.5 (0xb3993000) liblz4.so.1 => /usr/lib/arm-linux-gnueabihf/liblz4.so.1 (0xb3967000) libgcrypt.so.20 => /lib/arm-linux-gnueabihf/libgcrypt.so.20 (0xb388d000) libgpg-error.so.0 => /lib/arm-linux-gnueabihf/libgpg-error.so.0 (0xb3863000) -
@Piotrrr said in Could not load the Qt platform plugin "xcb" in "" problem.:
libxcb-xinput.so.0 => not found
this lib is not there
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Run the app with
export QT_DEBUG_PLUGINS=1and I got this:Got keys from plugin meta data ("xcb") QFactoryLoader::QFactoryLoader() checking directory path "/home/pi/platforms" ... Cannot load library /usr/local/qt5.15/plugins/platforms/libqxcb.so: (libxcb-xinput.so.0: cannot open shared object file: No such file or directory) QLibraryPrivate::loadPlugin failed on "/usr/local/qt5.15/plugins/platforms/libqxcb.so" : "Cannot load library /usr/local/qt5.15/plugins/platforms/libqxcb.so: (libxcb-xinput.so.0: cannot open shared object file: No such file or directory)" qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.So it's looking for this file in
/home/pi/platformsbut that directory doesn't exist, am I right? Where can I get/install this libxcb-xinput.so.0 from? -
@Piotrrr said in Could not load the Qt platform plugin "xcb" in "" problem.:
Where can I get/install this libxcb-xinput.so.0 from?
What OS is running on your device?
If Raspbian then it should be libxcb-xinput package. -
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@Piotrrr said in Could not load the Qt platform plugin "xcb" in "" problem.:
now the example app works
great, so please don't forget to mark your post as solved!
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I am facing a similar issue trying to cross-compile QT5.12.3 for the raspberry pi3 using arm-linux-gnueabihf-gcc-8.3.0 on Ubuntu LTS 20.04
My two centaves coin follows the qt.conf strategy
- Detect where the crosscompiled X11 backend pluggin is installed on yout target. Following the guides related with, it is usually deployed on /usr/local/qt5pi/plugins or similar
- Verify the object libqxcb.so is fully resolved on your host, below is my output after installing all dependencies
# ldd /usr/local/qt5pi/plugins/platforms/libqxcb.so linux-vdso.so.1 (0x7ed50000) /usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0x76f90000) libQt5XcbQpa.so.5 => /usr/local/qt5pi/examples/gui/analogclock/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x76e3e000) libfontconfig.so.1 => /lib/arm-linux-gnueabihf/libfontconfig.so.1 (0x76dda000) libfreetype.so.6 => /lib/arm-linux-gnueabihf/libfreetype.so.6 (0x76d37000) libz.so.1 => /lib/arm-linux-gnueabihf/libz.so.1 (0x76d0c000) libQt5Gui.so.5 => /usr/local/qt5pi/examples/gui/analogclock/plugins/platforms/../../lib/libQt5Gui.so.5 (0x76855000) libQt5DBus.so.5 => /usr/local/qt5pi/examples/gui/analogclock/plugins/platforms/../../lib/libQt5DBus.so.5 (0x767c1000) libQt5Core.so.5 => /usr/local/qt5pi/examples/gui/analogclock/plugins/platforms/../../lib/libQt5Core.so.5 (0x7632f000) libGLESv2.so.2 => /lib/arm-linux-gnueabihf/libGLESv2.so.2 (0x76310000) libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0x762e6000) libX11-xcb.so.1 => /lib/arm-linux-gnueabihf/libX11-xcb.so.1 (0x762d4000) libxcb-icccm.so.4 => /lib/arm-linux-gnueabihf/libxcb-icccm.so.4 (0x762c0000) libxcb-image.so.0 => /lib/arm-linux-gnueabihf/libxcb-image.so.0 (0x762ac000) libxcb-shm.so.0 => /lib/arm-linux-gnueabihf/libxcb-shm.so.0 (0x76299000) libxcb-keysyms.so.1 => /lib/arm-linux-gnueabihf/libxcb-keysyms.so.1 (0x76286000) libxcb-randr.so.0 => /lib/arm-linux-gnueabihf/libxcb-randr.so.0 (0x76269000) libxcb-render-util.so.0 => /lib/arm-linux-gnueabihf/libxcb-render-util.so.0 (0x76255000) libxcb-render.so.0 => /lib/arm-linux-gnueabihf/libxcb-render.so.0 (0x7623a000) libxcb-shape.so.0 => /lib/arm-linux-gnueabihf/libxcb-shape.so.0 (0x76227000) libxcb-sync.so.1 => /lib/arm-linux-gnueabihf/libxcb-sync.so.1 (0x76211000) libxcb-xfixes.so.0 => /lib/arm-linux-gnueabihf/libxcb-xfixes.so.0 (0x761fa000) libxcb-xinerama.so.0 => /lib/arm-linux-gnueabihf/libxcb-xinerama.so.0 (0x761e7000) libxcb-xkb.so.1 => /lib/arm-linux-gnueabihf/libxcb-xkb.so.1 (0x761c2000) libxcb.so.1 => /lib/arm-linux-gnueabihf/libxcb.so.1 (0x76193000) libXrender.so.1 => /lib/arm-linux-gnueabihf/libXrender.so.1 (0x7617a000) libXext.so.6 => /lib/arm-linux-gnueabihf/libXext.so.6 (0x7615b000) libX11.so.6 => /lib/arm-linux-gnueabihf/libX11.so.6 (0x76039000) libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0x75fb7000) libxkbcommon.so.0 => /lib/arm-linux-gnueabihf/libxkbcommon.so.0 (0x75f6e000) libxkbcommon-x11.so.0 => /lib/arm-linux-gnueabihf/libxkbcommon-x11.so.0 (0x75f57000) libdl.so.2 => /lib/arm-linux-gnueabihf/libdl.so.2 (0x75f44000) libstdc++.so.6 => /lib/arm-linux-gnueabihf/libstdc++.so.6 (0x75dfd000) libgcc_s.so.1 => /lib/arm-linux-gnueabihf/libgcc_s.so.1 (0x75dd0000) libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0x75c82000) libgthread-2.0.so.0 => /lib/arm-linux-gnueabihf/libgthread-2.0.so.0 (0x75c70000) libglib-2.0.so.0 => /lib/arm-linux-gnueabihf/libglib-2.0.so.0 (0x75b60000) libexpat.so.1 => /lib/arm-linux-gnueabihf/libexpat.so.1 (0x75b1f000) libuuid.so.1 => /lib/arm-linux-gnueabihf/libuuid.so.1 (0x75b08000) /lib/ld-linux-armhf.so.3 (0x76fb8000) libpng16.so.16 => /lib/arm-linux-gnueabihf/libpng16.so.16 (0x75acc000) libharfbuzz.so.0 => /lib/arm-linux-gnueabihf/libharfbuzz.so.0 (0x759ce000) libdbus-1.so.3 => /lib/arm-linux-gnueabihf/libdbus-1.so.3 (0x7597d000) libicui18n.so.63 => /lib/arm-linux-gnueabihf/libicui18n.so.63 (0x7572f000) libicuuc.so.63 => /lib/arm-linux-gnueabihf/libicuuc.so.63 (0x755a9000) libicudata.so.63 => /lib/arm-linux-gnueabihf/libicudata.so.63 (0x73bab000) libpcre2-16.so.0 => /lib/arm-linux-gnueabihf/libpcre2-16.so.0 (0x73b2f000) libdouble-conversion.so.1 => /lib/arm-linux-gnueabihf/libdouble-conversion.so.1 (0x73b0b000) libGLdispatch.so.0 => /lib/arm-linux-gnueabihf/libGLdispatch.so.0 (0x73a8c000) libxcb-util.so.0 => /lib/arm-linux-gnueabihf/libxcb-util.so.0 (0x73a77000) libXau.so.6 => /lib/arm-linux-gnueabihf/libXau.so.6 (0x73a64000) libXdmcp.so.6 => /lib/arm-linux-gnueabihf/libXdmcp.so.6 (0x73a4f000) libpcre.so.3 => /lib/arm-linux-gnueabihf/libpcre.so.3 (0x739d8000) libgraphite2.so.3 => /lib/arm-linux-gnueabihf/libgraphite2.so.3 (0x739a7000) libsystemd.so.0 => /lib/arm-linux-gnueabihf/libsystemd.so.0 (0x7390a000) libbsd.so.0 => /lib/arm-linux-gnueabihf/libbsd.so.0 (0x738e2000) librt.so.1 => /lib/arm-linux-gnueabihf/librt.so.1 (0x738cb000) liblzma.so.5 => /lib/arm-linux-gnueabihf/liblzma.so.5 (0x7389a000) liblz4.so.1 => /lib/arm-linux-gnueabihf/liblz4.so.1 (0x7386e000) libgcrypt.so.20 => /lib/arm-linux-gnueabihf/libgcrypt.so.20 (0x73794000) libgpg-error.so.0 => /lib/arm-linux-gnueabihf/libgpg-error.so.0 (0x7376a000)- Now the patch can be safetly written.
On your executable directory write a file qt.conf (which follows a .ini format) where you can specify the specifical QT context required to run your application, on this particular case we only need to adjust the plugins path. A full description can be read here
i.e .
pi@raspberrypi:/usr/local/qt5pi/examples/gui/analogclock $ tree . ├── analogclock ├── analogclock.pro ├── main.cpp ├── plugins -> /usr/local/qt5pi/plugins └── qt.conf 1 directory, 4 files pi@raspberrypi:/usr/local/qt5pi/examples/gui/analogclock $ cat qt.conf [Paths] Plugins=pluginsIHTH
PD: The qtbase main entry was deployed with the following spec
$ echo $CROSS_COMPILER_LOCATION /home/juanba/raspi/tools/cross-pi-gcc-8.3.0-2 $ ./configure -release -qt-xcb -xcb -opengl es2 -device linux-rasp-pi3-vc4-g++ -device-option CROSS_COMPILE=$(echo $CROSS_COMPILER_LOCATION)/bin/arm-linux-gnueabihf- -sysroot ~/raspi/sysroot -prefix /usr/local/qt5pi -extprefix /home/juanba/raspi/qt5pi -opensource -confirm-license -skip qtscript -skip qtwar -v -recheck -L$HOME/raspi//sysroot/usr/lib/arm-linux-gnueabihf -I$HOME/raspi//sysroot/usr/include/arm-linux-gnueabihf
