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

[dziko147]

@JonB Exact . I Set environment variable QT_DEBUG_PLUGINS=1 in Qtcreator .
@jsulm from source

[jsulm]

@dziko147 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

in Qtcreator

On RPi?

[jsulm]

@dziko147 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

from source

Then probably XCB plug-in was not build because of missing dependencies. You should check config.log file to get more information.

[dziko147]

@jsulm no in Host

[jsulm]

@dziko147 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

in Host

Do you run your app from QtCreator remotely on your device?

[dziko147]

@jsulm Yes

[jsulm]

@dziko147 OK, then check config.log from your Qt build to see why XCB plug-in was not enabled.

[dziko147]

@jsulm you mean in my host machine ?

[jsulm]

@dziko147 Yes. I guess you cross compiled Qt on your host machine?

[dziko147]

@jsulm exact .
I checked my config.log
I found this :

test config.qtbase_network.tests.openssl11 succeeded
looking for library xkbcommon
Trying source 0 (type pkgConfig) of library xkbcommon ...
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --exists --silence-errors xkbcommon '>=' 0.5.0
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --modversion xkbcommon '>=' 0.5.0
> 0.8.2
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --libs-only-L xkbcommon '>=' 0.5.0
> -L/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --libs-only-l xkbcommon '>=' 0.5.0
> -lxkbcommon
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --cflags xkbcommon '>=' 0.5.0
+ cd /home/**/raspi/config.tests/xkbcommon && PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /home/**/raspi/qtbase/bin/qmake "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += shared warn_off console single_arch" "QMAKE_CFLAGS += --sysroot=/home/**/raspi/sysroot" "QMAKE_CXXFLAGS += --sysroot=/home/**/raspi/sysroot" "QMAKE_LFLAGS += --sysroot=/home/**/raspi/sysroot" -early "CONFIG += cross_compile" 'QMAKE_USE += xkbcommon' 'QMAKE_LIBS_XKBCOMMON = /home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/libxkbcommon.so' /home/**/raspi/config.tests/xkbcommon
+ cd /home/**/raspi/config.tests/xkbcommon && MAKEFLAGS= /usr/bin/make
> /home/**/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++ -c -march=armv8-a -mtune=cortex-a53 -mfpu=crypto-neon-fp-armv8 -mfloat-abi=hard --sysroot=/home/**/raspi/sysroot --sysroot=/home/**/raspi/sysroot -O2 -std=gnu++11 -w -fPIC  -I. -I/home/**/raspi/qt-everywhere-src-5.12.10/qtbase/mkspecs/devices/linux-rasp-pi3-g++ -o main.o main.cpp
> /home/**/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++ -mfloat-abi=hard --sysroot=/home/**/raspi/sysroot --sysroot=/home/**/raspi/sysroot -Wl,-O1 -Wl,-rpath-link,/home/**/raspi/sysroot/opt/vc/lib -Wl,-rpath-link,/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link,/home/**/raspi/sysroot/lib/arm-linux-gnueabihf -o xkbcommon main.o   /home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/libxkbcommon.so   
 => source accepted.
test config.qtbase_gui.libraries.xkbcommon succeeded
looking for library xcb
Trying source 0 (type pkgConfig) of library xcb ...
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --exists --silence-errors xcb '>=' 1.9
pkg-config did not find package.
  => source produced no result.
Trying source 1 (type inline) of library xcb ...
None of [libxcb.so libxcb.a] found in [] and global paths.
  => source produced no result.
test config.qtbase_gui.libraries.xcb FAILED
looking for library opengl_es2
Trying source 0 (type pkgConfig) of library opengl_es2 ...
+ PKG_CONFIG_SYSROOT_DIR=/home/**/raspi/sysroot PKG_CONFIG_LIBDIR=/home/**/raspi/sysroot/usr/lib/pkgconfig:/home/**/raspi/sysroot/usr/share/pkgconfig:/home/**/raspi/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig /usr/bin/pkg-config --exists --silence-errors glesv2
pkg-config did not find package.
  => source produced no result.

[JKSH]

@dziko147 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

I checked my config.log
I found this :

What does it say about the xcb library? Does that give you any clues?

[dziko147]

@JKSH there is no xcb plugin/lib .
So Can I install it independently

[jsulm]

@dziko147 What @JKSH means (I guess) is this:

None of [libxcb.so libxcb.a] found in [] and global paths

So, it seems that your sysroot does not contain libxcb and libxcb-dev.
Install that lib package and its dev package in your sysroot and build XCB plug-in.

[dziko147]

@jsulm there is no tutoriel or example to use it ?

[SGaist]

Hi,

The usual way is to install all the dependencies dev packages on your target and copy the root file system back on your host machine for use with your cross-compiler.