Not Able to run Qt Application in BeagleBone Black with Qt 5.7

[Milav]

@jsulm how can i built Qt 5.7 using cross complier?

can you please suggest me a steps, how to run application on BBB using qt5.7?

i add path of complier,path of debugger, path of Qt Vesrion on build and run tab of options tool.

[jsulm]

@Milav I cannot suggest you a step-by step instructions as I never cross compiled Qt for BBB.
But you can take a look at this: https://wiki.qt.io/RaspberryPi_Beginners_Guide
It is for RaspberryPi but it will be similar for BBB.
You could also check whether there is already a Qt build for BBB available somewhere.

[Milav]

@jsulm , until now I am able to configure the QT 5.7.0.
I cross compile the QT for BeagleBone Black. but when i run the simple application qt give following error..

"stdin: is not a tty
/home/debian/Helloworldapp: error while loading shared libraries: libQt5Widgets.so.5: cannot open shared object file: No such file or directory
Application finished with exit code 127."

how can i solve this error?

Am i do wrong configuration?

Is there a any QT package download on Beagle Bone Black?

please suggest me?

[jsulm]

@Milav Did you copied the Qt libs (like libQt5Widgets.so.5) together with your application to the target device?
See here how to deploy a Qt application on Linux: http://doc.qt.io/qt-5/linux-deployment.html

I don't know whether there is a Qt build for BBB, you should search a bit on the Internet.

[Milav]

@jsulm I can not get you and this link: http://doc.qt.io/qt-5/linux-deployment.html
please explore me more....
can add some Lib path in my qt project file. or i add something more on configure option.
is this issues related to LD_LIBRARY_PATH ?
please suggest me...

[jsulm]

@Milav Please read the "Creating the Application Package" part of the link I sent you.
There is a script you can use to start your application:

#!/bin/sh
appname=`basename $0 | sed s,\.sh$,,`

dirname=`dirname $0`
tmp="${dirname#?}"

if [ "${dirname%$tmp}" != "/" ]; then
dirname=$PWD/$dirname
fi
LD_LIBRARY_PATH=$dirname
export LD_LIBRARY_PATH
$dirname/$appname "$@"

Put all needed Qt libraries in the same directory as your executable. In addition you will need some plugins, so create a subdirectory "plugins" and put there needed plugins.

[Milav]

@jsulm hello,

The above error (error while loading shared libraries: libQt5Widgets.so.5) is solved. thanks a lot..
I just copy whole install directory (/usr/local/QT5.7.0) to Beagle Bone Black (/usr/local) path.

but when I again build the qt project, it will give following error.

stdin: is not a tty
This application failed to start because it could not find or load the Qt platform plugin "eglfs"
in "".

Available platform plugins are: linuxfb, minimal, offscreen.

Reinstalling the application may fix this problem.
bash: line 1: 2072 Aborted DISPLAY=':0.0' QWS_MOUSE_PROTO='LinuxInput:/dev/input/event1' /home/debian/Helloworldapp -qws
Application finished with exit code 134.

can you help me to resove this issues?

[jsulm]

@Milav said in Not Able to run Qt Application in BeagleBone Black with Qt 5.7:

eglfs

Does your Qt build have the eglfs plug-in? Plug-ins are in plugin subdirectory.

[Milav]

@jsulm no, there is not eglfs.so library file in installation directory(/usr/local/Qt5.7.0/plugnis/platforms/) of qt.

when i run application manually with ./App - platform linuxfb it is run but it gives following error

QFontDatabase: Cannot find font directory /usr/local/Qt-5.7.0/lib/fonts.
Note that Qt no longer ships fonts. Deploy some (from http://dejavu-fonts.org for example) or switch to fontconfig.
QFontDatabase: Cannot find font directory /usr/local/Qt-5.7.0/lib/fonts.
Note that Qt no longer ships fonts. Deploy some (from http://dejavu-fonts.org for example) or switch to fontconfig.
QFontDatabase: Cannot find font directory /usr/local/Qt-5.7.0/lib/fonts.
Note that Qt no longer ships fonts. Deploy some (from http://dejavu-fonts.org for example) or switch to fontconfig.
QFontDatabase: Cannot find font directory /usr/local/Qt-5.7.0/lib/fonts.
Note that Qt no longer ships fonts. Deploy some (from http://dejavu-fonts.org for example) or switch to fontconfig.

which is needed platform for Beagle bone black debian Os? as per your knowledge?

what is the next step? to resolve this error?

[jsulm]

@Milav It looks like you need to provide the fonts as well, they should be located in /usr/local/Qt-5.7.0/lib/fonts according the warning. So copy them from your host Qt to /usr/local/Qt-5.7.0/lib/fonts on your target device.

[Milav]

@jsulm ..Hello,

I found inbuilt Fonts Directory of Qt5.7.0, but the result of that find is null.
than I download the fontconfig library (fontconfig-2.12.1)from external sources.
Than compile that library, and than it shows the fonts lib. in /usr/share/fonts .
and than copy this folder to target device in /usr/local/Qt5.7.0/lib/ path..
after doing this the above error was removed..but still i can not see the font in application.
what is the problem?

[jsulm]

@Milav said in Not Able to run Qt Application in BeagleBone Black with Qt 5.7:

i can not see the font in application

What do you mean? You cannot see any text in your application? Or you cannot select one of the fonts?

[Milav]

@jsulm
i cannot see any text in my application.....

[jsulm]

@Milav Which font does your application use? Is this font in /usr/local/Qt5.7.0/lib ?

[Milav]

@jsulm
I use "DejaVu Sans" font use in application.

and these fonts is available in this path:-
/usr/local/Qt-5.7.0/lib/fonts/truetype/ttf-dejavu

in that directroy ,
DejaVuSans-Bold.ttf DejaVuSansMono-Bold.ttf DejaVuSansMono.ttf DejaVuSans.ttf DejaVuSerif-Bold.ttf DejaVuSerif.ttf

files are stored.

[jsulm]

@Milav Try to print the content of the list returned by http://doc.qt.io/qt-5/qfontdatabase.html#applicationFontFamilies to the standard output and see what you get.

[Milav]

@jsulm
i will try http://doc.qt.io/qt-5/qfontdatabase.html#applicationFontFamilies , but still i can not see the text in qt application on Beaglebone black gui window...

still i miss some package of fonts in Beaglebone black.

can anyone suggest me for this package.?

[Milav]

Hello @jsulm

I just found that when i write the following command in build directory that enable the fontconfig , and XCB package....

#./configure -prefix /usr/local/qt_install

but when i use following command in build directory that disable the fontconfig and xcb package.

#./configure -prefix /usr/local/qt_install -xplatform linux-arm-gnueabihf -device linux-beagleboard-g++ -device-option CROSS_COMPILE=/opt/gcc-arm-linux/bin/arm-linux-gnueabihf-

so where is the problem?

[jsulm]

@Milav Most probably your sysroot does not contain header files and libraries for fontconfig and xcb. You can see what is missing by adding -v parameter to configure.

[Milav]

Hello ,

I added -sysroot in configuration command so that all header and libraries are to be added.

I used external SD card as a sysroot path. In SD card i use same image version as in target device image.

but this give me a following error...

Project ERROR: No module claims plugin type 'scenegraph'
make[4]: *** [sub-softwarecontext-make_first] Error 3
make[4]: Leaving directory /root/qt_build_23nov/qtdeclarative-render2d/src/plugins/scenegraph' make[3]: *** [sub-scenegraph-make_first] Error 2 make[3]: Leaving directory /root/qt_build_23nov/qtdeclarative-render2d/src/plugins'
make[2]: *** [sub-plugins-make_first] Error 2
make[2]: Leaving directory /root/qt_build_23nov/qtdeclarative-render2d/src' make[1]: *** [sub-src-make_first] Error 2 make[1]: Leaving directory /root/qt_build_23nov/qtdeclarative-render2d'
make: *** [module-qtdeclarative-render2d-make_first] Error 2

so where is the problem?