Problems compiling Qt 5.8 on Debian 8.7.1

Harry123 · wrote on 18 Mar 2017, 18:26

I have built and installed from source Qt version 5.8 on Debian 8.7.1.

While linking my program I get errors like this :

/usr/local/Qt-5.8.0/lib/libQt5MultimediaWidgets.so: undefined reference to `QGLContext::currentContext()@Qt_5'
/usr/local/Qt-5.8.0/lib/libQt5MultimediaWidgets.so: undefined reference to `QGLShaderProgram::setAttributeArray(char const*, float const*, int, int)@Qt_5'
/usr/local/Qt-5.8.0/lib/libQt5MultimediaWidgets.so: undefined reference to `QGLContext::getProcAddress(QString const&) const@Qt_5'

Am I missing some package or compile option ?

SGaist · wrote on 18 Mar 2017, 22:49

Hi,

Can you show your .pro file ?

Harry123 · wrote on 19 Mar 2017, 10:03

About my .pro file : It is very simple and there is nothing special about it. It has worked just fine on Windows and Kubuntu.

This is apparently a Debian problem when configuring Qt.

I found a reference to it in this post :

I made a mistake in 'configure' script. I didn't know that Debian had a separate package for QtGL extension, and 'configure' checks only if GL library is installed and if it is it assumes that QtGL is built-in into Qt (as in my RedHat ). You will have to configure without GL then.

It would take somebody more knowledgeable than me to fully understand the above.

So I have tried to compile Qt using configure -no-opengl, but have now compilation errors in Qt itself like this:

error: undefined reference to 'vtable for QQuickFramebufferObject'

The manual describes this class as :

The QQuickFramebufferObject class is a convenience class for integrating OpenGL rendering using a framebuffer object (FBO) with Qt Quick.

What more do I need to do to to get a viable version of Qt on Debian ?

SGaist · wrote on 19 Mar 2017, 18:54

Did you install the OpenGL dev packages on your system ?

Harry123 · 20 Mar 2017, 02:10

Yes, package libgl1-mesa-dev is installed.

I'm ready to give up Qt on Debian.

SGaist · wrote on 19 Mar 2017, 21:16

When calling configure again, did you do it from a clean state ?

In any case, what is the configure line you used to build Qt ?

JiujiuTong · wrote on 20 Mar 2017, 02:10

@Harry123
hi, do you find way out ?
i also meet the same problem on cross compiling for my rpi3. my ENV is Qt5.7 + centos (x64).
https://forum.qt.io/topic/76928/qt-on-rpi3-debug-info-how-to-fix/37

Harry123 · wrote on 20 Mar 2017, 13:10

@SGaist - A very clean slate : I deleted the folder and re-unpacked from the tar.gz file.

@JiujiuTong - No solution. I'm trying another Linux distribution before putting up a bug report.

SGaist · 21 Mar 2017, 00:47

What exact configure options did you give ?

JiujiuTong · S SGaist 20 Mar 2017, 21:45

@SGaist
my configure is :
"./configure -release -opengl es2 -skip webengine -device linux-rasp-pi2-g++ -device-option CROSS_COMPILE=~/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf- -sysroot ~/raspi/sysroot -opensource -confirm-license -make libs -prefix /usr/local/qt5pi -extprefix ~/raspi/qt5pi -hostprefix ~/raspi/qt5 -v "
my host is centos 7, the target is raspberry pi3, trying with cross compiler way,and should i take "-no-opengl" do you think?

SGaist · wrote on 21 Mar 2017, 08:14

@JiujiuTong wait a minute, there's a problem here, you are mixing a cross-compilation problem which is not related to the problem at hand for @Harry123 which is just trying to compile Qt for its desktop.

@Harry123 Can you share the configure line you used to compile Qt on your machine ?

Harry123 · wrote on 21 Mar 2017, 10:12

@SGaist :
I first tried ./configure -debug which gave me the problem of QGLContext.
I next tried ./configure -debug -no-opengl which gave me the problem of QQuickFramebufferObject.

SGaist · wrote on 21 Mar 2017, 11:32

Can you check with -opengl desktop ?

I'd recommend doing out of source builds. That way you can just nuke the build folder is something goes wrong.

Harry123 · wrote on 21 Mar 2017, 13:11

@SGaist :

It wouldn't work with -opengl desktop because already when I used just ./configure I had a message about opengl missing.

I have anyway given up on compiling the sources - configure simply doesn't do the job correctly with the default flags, and each try takes hours.

I have taken to using instead the online installer, which installs a viable version optionally with the sources.

Would you know if I can use the online installer to install directly into the /usr folders such as /usr/bin, /usr/include etc. ? Or after the installation to copy the installed folders to there?

SGaist · wrote on 21 Mar 2017, 13:27

In that case it means you don't have the OpenGL dev package installed.

You can't and you shouldn't even try. You'll be clearly messing with your distribution installation which is a very bad idea.

If you want to share your Qt installation with several users on your machine then use the default which is /opt otherwise, you can also simply install it in your home folder.

Harry123 · wrote on 21 Mar 2017, 13:43

@SGaist :
I'm the only user and the installation is on a VM.
I would like to reproduce the effect of Qt being installed from the repository, even though version 5.8 is not in it.

SGaist · wrote on 21 Mar 2017, 14:10

That's not a good idea. You are trying to replace your system Qt installation which has been built by the Debian folks in a state known to work for them.

Why do you want to replace it ?

If you want the Debian variant of Qt 5.8 then install the experimental version of Debian.

Harry123 · wrote on 21 Mar 2017, 15:34

@SGaist :
OK, I gave up on this idea. Unfortunate that a repository does not exist for QT 5.8 (Debian experimental only contains parts).
I will stay with the online installation and will give up on my ambition to compile Qt.
Too bad, as I wanted a real debug version for easier debugging.

SGaist · wrote on 21 Mar 2017, 20:18

Like I already wrote, there seems to be something missing on your system.

You should be able to build Qt 5.8 without any problem on Debian.

Harry123 · wrote on 22 Mar 2017, 20:24

@SGaist : Unfortunately we live in an imperfect world.
Thanks for your help - much appreciated.

I will mark this post as solved, even though it's not really, but I have no more time to spend on this.