[SOLVED] Qt on Slackware Linux

andreyc · wrote on 13 Mar 2014, 16:45

qmake-qt5 is a regular qmake that was renamed by a package maintainer to avoid collisions with qt4.

I would suggest you to use Qt from "qt-project downloads":http://qt-project.org/downloads
In this case you will get Qtcreator and Qt framework.
The installer will put everything under one directory which you can change during installation. By default it is $HOME/Qt5.2.1

If you prefer to keep the Qt5 package and removed qt4 then rename qmake-qt5 to qmake

Sleicreider · wrote on 14 Mar 2014, 08:38

using the qt-installer and it's .run file, solved my problem :) thank you

compiler is doing fine, but it shows a few errors:

libGL error: failed to load driver: i965
libGL error: Try again with LIBGL_DEBUG=verbose for more details.

any solution for this ?

Sleicreider · wrote on 14 Mar 2014, 08:47

btw: the error only appears with a QT GUI project
console application works fine

andreyc · wrote on 14 Mar 2014, 15:58

Qt tries to use opengl and looks like your video setup does not have it.
Check what LIBGL_DEBUG tells.
Maybe you will need to update video drivers and or install mesa libraries.
I have not seen this problem on my linux boxes (fedora and ubuntu) so I can not tell much here.

Sleicreider · wrote on 14 Mar 2014, 16:22

oh, i'm working on a hp workstation here, could be the reason for this error, because it has no graphic card(just intel xeon integraded graphics) which normally provides opengl.

andreyc · wrote on 14 Mar 2014, 16:57

It can be the reason.

Do you use opengl in your application? If so, then you may need to install mesa libraries and use software opengl.
What messages LIBGL_DEBUG=verbose gives ?
Does qtcreator from downloaded Qt gives the same error?
If you try to build Qt examples do they provide the same error?

Sleicreider · wrote on 14 Mar 2014, 18:12

Actually i don't need OpenGL on this pc,
the error message just appears(application output) in a GUI(mainwindow etc.) project when I compile it, but the application itself works fine.

the console application works perfectly.

andreyc · wrote on 15 Mar 2014, 18:00

Just out of curiosity. If you will set LIBGL_DEBUG=verbose before a compilation then maybe you will see who is the reason for the message.
something like this
@
export LIBGL_DEBUG=verbose
qmake
make
@

Sleicreider · wrote on 17 Mar 2014, 08:47

sry for the question, but where you want me to write this down?

andreyc · wrote on 17 Mar 2014, 14:29

Run these commands in a shell command prompt.

Run it in separate directory from your project directory.
For example if your .pro file is located in
/home/user/workspace/myproject
then
@
cd /home/user/workspace/
mkdir build-myproject
cd build-myproject
export LIBGL_DEBUG=verbose
qmake -recursive ../myproj
make
@

Sleicreider · wrote on 17 Mar 2014, 14:35

it says: bash: qmake-recursive: command not found

andreyc · wrote on 17 Mar 2014, 15:35

There is a space between qmake and -recursive

Sleicreider · wrote on 17 Mar 2014, 16:12

it says: qmake command not found,
also can't find a qmake or qmake-qt5 with

which qmake

or

which qmake-qt5

btw: i used the online installer straight from the qt website(.run)

andreyc · wrote on 17 Mar 2014, 16:18

The try to run qmake with full path.
Let say you have Qt installed in /home/user/Qt5.2.1
then run it
@
/home/user/Qt5.2.1/5.2.1/gcc/bin/qmake
@

Sleicreider · wrote on 18 Mar 2014, 08:01

thats the output in the terminal:
@
bash-4.2$ make
/home/reidom1994/Qt/5.2.1/gcc_64/bin/uic ../GUI_Hello_World/mainwindow.ui -o ui_mainwindow.h
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt/5.2.1/gcc_64/mkspecs/linux-g++ -I../GUI_Hello_World -I../../Qt/5.2.1/gcc_64/include -I../../Qt/5.2.1/gcc_64/include/QtWidgets -I../../Qt/5.2.1/gcc_64/include/QtGui -I../../Qt/5.2.1/gcc_64/include/QtCore -I. -I. -I. -o main.o ../GUI_Hello_World/main.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt/5.2.1/gcc_64/mkspecs/linux-g++ -I../GUI_Hello_World -I../../Qt/5.2.1/gcc_64/include -I../../Qt/5.2.1/gcc_64/include/QtWidgets -I../../Qt/5.2.1/gcc_64/include/QtGui -I../../Qt/5.2.1/gcc_64/include/QtCore -I. -I. -I. -o mainwindow.o ../GUI_Hello_World/mainwindow.cpp
/home/reidom1994/Qt/5.2.1/gcc_64/bin/moc -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt/5.2.1/gcc_64/mkspecs/linux-g++ -I../GUI_Hello_World -I../../Qt/5.2.1/gcc_64/include -I../../Qt/5.2.1/gcc_64/include/QtWidgets -I../../Qt/5.2.1/gcc_64/include/QtGui -I../../Qt/5.2.1/gcc_64/include/QtCore -I. -I. -I. ../GUI_Hello_World/mainwindow.h -o moc_mainwindow.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt/5.2.1/gcc_64/mkspecs/linux-g++ -I../GUI_Hello_World -I../../Qt/5.2.1/gcc_64/include -I../../Qt/5.2.1/gcc_64/include/QtWidgets -I../../Qt/5.2.1/gcc_64/include/QtGui -I../../Qt/5.2.1/gcc_64/include/QtCore -I. -I. -I. -o moc_mainwindow.o moc_mainwindow.cpp
g++ -Wl,-O1 -Wl,-rpath,/home/reidom1994/Qt/5.2.1/gcc_64 -Wl,-rpath,/home/reidom1994/Qt/5.2.1/gcc_64/lib -o GUI_Hello_World main.o mainwindow.o moc_mainwindow.o -L/home/reidom1994/Qt/5.2.1/gcc_64/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread @

andreyc · wrote on 18 Mar 2014, 14:25

I don't see any error message in the output.
Does it mean that issue is gone ?
Does your app works without any error messages ?

Sleicreider · wrote on 19 Mar 2014, 07:47

It still appears in the application output :
Starting /home/user/QT C++/myproject/myproject...
libGL error: failed to load driver: i965
libGL error: Try again with LIBGL_DEBUG=verbose for more details.

Application still works fine.

I have no idea, but it's working so doesn't matter i think xD

andreyc · wrote on 19 Mar 2014, 17:40

What if you will run your app with LIBGL_DEBUG=verbose
something like
@
export LIBGL_DEBUG=verbose
/home/user/QT C++/myproject/myproject…
@

If it does not bother you then you can run your app and redirect all output to /dev/null
@
/home/user/QT C++/myproject/myproject… > /dev/null 2>&1
@

Sleicreider · wrote on 20 Mar 2014, 07:58

first one without root:

libGL: OpenDriver: trying /usr/lib64/xorg/modules/dri/i965_dri.so
libGL error: failed to open drm device: Permission denied
libGL error: failed to load driver: i965
libGL: OpenDriver: trying /usr/lib64/xorg/modules/dri/swrast_dri.so

with root:
Qt: Session management error: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed
libGL: OpenDriver: trying /usr/lib64/xorg/modules/dri/i965_dri.so
libGL: Can't open configuration file /root/.drirc: No such file or directory.

I also tried the second one.
Whats the reason, to redirect the output to /dev/null ^^

andreyc · wrote on 20 Mar 2014, 16:43

About /dev/null.
It will hide your error messages and you will not worry about it. :-)

Some GNU/Linuxes have a "video" group and only members of that group are allowed to use opengl.
Could you check if Slackware has such restriction. If so then add your self to that video group re-login and try to run your app again.