[SOLVED] How to install QT under the Raspbian image?

Pinkypanzer

i executed apt-get install qt50-snapshot
but where can i find the configure-script?
and what does sysroot mean?

AcerExtensa

Which configure script? qt50-snapshot installs only Qt libs, include files & qmake with tools... You do not need to configure and build Qt on your raspbian... just use qmake to generate Makefile for your project and build it.

Sysroot - is system root folder tree of your system, it is only needed if you want buld Qt by yourself.

What you actually need?

Just build programs with Qt on your RPi? qt50-snapshot should be installed on your RPi.
Build program with Qt on your Local PC for RPi? You then need cross-compiler, sysroot and cross-compiled Qt on your Local PC and installed qt50-snapshot on your RPi
Build Qt for RPi? you then need cross-compiler and sysroot on your Local PC

There is pretty nice articles on the wiki for all kind of situations: "Qt 5 and Raspberry Pi":http://qt-project.org/wiki/Qt-RaspberryPi

Pinkypanzer

If I use the second option: is it enough to say apt-get install qt50-snapshot or do I have to do additional actions to install the snapshot?

AcerExtensa

yes. installed qt50-snapshot on RPi is enough to run program cross-compiled on your Local PC.
Just follow this "tutorial":http://qt-project.org/wiki/Create#QtonPi_App_SDK to cross-compile your app.

Pinkypanzer

But after installing the snapshot on the pi, cross-compiling the hello-world-app and deploying it I get the messagelib

error while loading shared libraries : QtQuick.so.5: cannot open shared object file: No such file or directory

do I have to do more than to say apt-get install qt50-snapshot?

AcerExtensa

Look into the /opt/ path, can you see "vt" & "qt5" folder? Look into the /opt/qt5/lib which libraries are installed. You should have /opt/qt5/lib/libQtQuick.so.5 there.
If Qt libs are installed correctly, but you still can't deploy and run your app, check with ldd(on the RPi) if all dependency for your app are found. just run:
@
ldd /path/to/your/hello-qtonpi
@

you can also check if all dependency for Qt is there:
@
readelf -d /opt/qt5/lib/libQtCore.so.5.0.0
readelf -d /opt/qt5/lib/libQtQuick.so.5.0.0
@

Pinkypanzer

There is no qt5 or vt in my opt-folder

Pinkypanzer

ldd says : not a dynamic executable

the readelf commands seem to work even if the folder is /opt/qt50-snapshot/lib. does this matter?

Pinkypanzer

do I have to use special settings in the pro file or otherwere in the project?

Pinkypanzer

Is it possible that I have to use another qmake to cross-compile for the wheezy than for the original qtonpi image?

Pinkypanzer

can be solved by

export LD_LIBRARY_PATH=/opt/qt50-snaphot/lib

before running the qt-program.

jcverdie

I ran into the same problem, but in my case it comes from a custom QT5 build (not the snapshot).
Anyway, if followed http://qt-project.org/wiki/RaspberryPi_Beginners_Guide
and qt ended being installed not in opt but in /usr/local/qt5pi/
libQtQuick.so.5.0.0 is in the lib subfolder but setting LD_LIBRARY_PATH does not change anything which is quite surprising, and as for Pinkypanzer the ldd tells me hello-qtonpi is not an executable :(

Any other clue?

Pinkypanzer

where did you execute it? via QtCreator or locally on the pi?
do you have the rights to execute it?

jcverdie

Both give the same result: running from QtCreator and running locally give the same error message

Yes, my binaries are in 644 mode

Pinkypanzer

now I see there's an error in my post. it has to be
export LD_LIBRARY_PATH=/opt/qt50-snapshot/lib
maybe this is your problem? you have to link the lib-folder

jcverdie

Indeed I've done that, but qt is not installed in opt for me, it is in /usr/local/qt5pi/lib !
And obviously I did not picked up the path, it came out of the box from the guidelines :(

Pinkypanzer

in QT CREATOR you have to set the the path in the system environment

cited from the beginners guide:
At last, add the LD_LIBRARY_PATH on the “System Environment” and set it to “/usr/local/qt5pi/lib”

In my case the path would be "/opt/qt50-snapshot/lib"

Pinkypanzer

Then I'm sorry, I don't know what your problem is.
Did you check the path is available at you pi and you have the rights to read from it?

pdsuk

@jcverdie

I followed the beginners guide like yourself also and ran into the same problem.

Apps deployed and executed from within QtCreator ran correctly on the device but if I went to the command line on the RPi itself, I couldn't execute them (libQtQuick.. not found)

Running: export LD_LIBRARY_PATH=/usr/local/qt5pi/lib/

Fixes this problem but only when logged in as root!

If I export LD_LIBRARY_PATH as user 'pi' I still cannot execute the binary (same error as before).

Stranger still, QtCreator which can deploy and run the binary correctly, is logging in via ssh with user 'pi' !

Any ideas why this is happening?

[SOLVED] How to install QT under the Raspbian image&#63;

[SOLVED] How to install QT under the Raspbian image?