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

jsulm

@Milav You need Qt built using your cross compiler. You cannot use Qt x86 build on ARM. Build Qt with your cross compiler and use it then.

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.