[SOLVED] gcc not recognized in QT after installation

developSomething

@koahnig
It is hooray again!
Now with gcc-4.9 my choice is both allowed and accepted.
I have a real compiler in QT set up now!

Next problem:
the build stops with the following error:
g++: command not found

My guess is it is about the qmake build step which is as following
qmake: qmake testwin.pro -r -spec linux-g++ CONFIG+=debug

SGaist

Let's add some voodoo:
sudo apt-get install build-essential

developSomething

@SGaist
my voodoo capabilities did not succeed
here is the result:
Paketlisten werden gelesen... Fertig
Abhängigkeitsbaum wird aufgebaut.
Statusinformationen werden eingelesen.... Fertig
E: Paket build-essential kann nicht gefunden werden.

translation:
the package build-essential can not be found

SGaist

Was ? Oo

That's something pretty strange then…

You can find it listed here

Do you have a special install of Ubuntu Trusty ?

In any case, you can also just call sudo apt-get install g++ but still it's puzzling

developSomething

@SGaist
Now the compiler g++ is installed and working!
Third hooray!

But the first testproject build stops with the issue:
cannot find -lGL

SGaist

That one has been covered many times in this forum: you are missing the OpenGL dev library

sudo apt-get install libgl1-mesa-dev

developSomething

@SGaist
It is the same result as above
Paketlisten werden gelesen... Fertig
Abhängigkeitsbaum wird aufgebaut.
Statusinformationen werden eingelesen.... Fertig
E: Paket libgl1-mesa-dev kann nicht gefunden werden.

I dont know if it has to do wih my Ubuntu 14.04LTS, i downloaded the official iso and made a dvd from it to install on my Lenovo PC
so it should be a normal installation?!

And a more general question: isn't there a more complete package for qt-installation? I mean this is really the hard way to get one error fixed after the other. One surprise follows the next.
I mean without your help i wouldn't be able to get anything done within weeks?!

koahnig

@developSomething
No, there no more complete packages available.
You are struggling with the different components of your linux distro. They may be depend on each distro and have licenses. This cannot be easily distributed within one package. Unfortunately, it is the same as with windows.

SGaist

One thing you can do that might help is to install the dev packages of Qt from Ubuntu's repository but at this point there seems to be strange things going on. Not finding build-essential is really not normal, what sources does apt use to retrieve the packages ?

developSomething

this is what the terminal shows:

x@x-ThinkCentre-A58:~$ apt
apt 1.0.1ubuntu2 für i386, kompiliert am Oct 28 2014 20:57:14
Usage: apt [options] command
CLI for apt.
Basic commands:
list - list packages based on package names
search - search in package descriptions
show - show package details
update - update list of available packages
install - install packages
remove - remove packages
upgrade - upgrade the system by installing/upgrading packages
full-upgrade - upgrade the system by removing/installing/upgrading packages
edit-sources - edit the source information file

SGaist

What does apt-cache search build-essential return ?

SGaist

Also, what do you have in /etc/apt/sources.list ?

developSomething

@SGaist
What does apt-cache search build-essential return ?

It returns nothing.

and this is the content of /etc/apt/sources.list:

# deb cdrom:[Ubuntu 14.04.2 LTS _Trusty Tahr_ - Release i386 (20150218.1)]/ trusty main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

## Major bug fix updates produced after the final release of the
## distribution.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.


## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu trusty partner
# deb-src http://archive.canonical.com/ubuntu trusty partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu trusty main
deb http://archive.ubuntu.com/ubuntu trusty restricted
deb-src http://extras.ubuntu.com/ubuntu trusty main

SGaist

Silly question but did you run apt-get updateafter you installed your system ?

developSomething

Now that i have tried everything mentioned another idea came to my mind:

Could it be possible it is my IP which is disliked by ubuntu? therefor only offering certain packages, excluding dev?

(moderation comment: we don't think there is a global conspiracy on Ubuntu packages, and looks like the problem was solved below)

JKSH

Hi,

@developSomething said:

and this is the content of /etc/apt/sources.list:

I see that you don't have any official repositories available. See https://help.ubuntu.com/community/Repositories/Ubuntu to add them. (At the very least, you need the "Main" repository. I also suggest adding "Universe" and "Restricted" to make Ubuntu nicer to useable.)

Then, try downloading the packages again.

isn't there a more complete package for qt-installation? I mean this is really the hard way to get one error fixed after the other. One surprise follows the next.

I've been using Ubuntu as a secondary computer for many years now. All this while, the only things I've needed to do to develop with Qt on Ubuntu are:

Install Ubuntu
Install g++
Install OpenGL development libraries (Mesa)
Install Qt

You're having difficulties because your machine has been misconfigured somewhere. (Usually,some repositories are enabled by default as soon as you install Ubuntu.)

Maybe this is kind of a location-based-service, meaning, well...
In my neighborhood there are living a lot of people from all over the world, including many muslims.
Could it be possible it is my IP which is disliked by ubuntu? therefor only offering certain packages, excluding dev?

Given that Canonical wants Ubuntu to spread all over the world, I'd be very surprised if they did this. However, you could ask at https://askubuntu.com to verify.

Anyway, I don't see how Muslims are related to your issue.

developSomething

@JKSH
thanks to your little install guide now everything works fine!

all i had to do was remove the whole ubuntu installation and restart from scratch.

Surprisingly the repositories were all set up correctly by default, maybe it was because i have chosen the default US-english installation instead of the german one ..^^

I would even be willing to add SOLVED to the title of the thread
if only i knew how to?

koahnig

@developSomething
How to mark as solved?

Simply go to the first post where you started. Press the gear wheel on the very right and select the left (Edit) symbol.
Go to your title line. Add there [solved] in the beginning of line.