title: Can't run projects in QtCreator 2.8.1...?
body: <p>I used QtCreator on Elementary OS Luna for quite some time, then I had to reinstall the system. After clean install I installed Qt SDK from <a href="https://qt-project.org/downloads" rel="nofollow">https://qt-project.org/downloads</a>.</p>
  
  <p>I created a sample, template project and hit Run. There was an error about no compiler set... so I installed g++ via <code>sudo apt-get install g++</code>.</p>
  
  <p>OK, I pushed it a bit further. Now I am getting two errors:</p>
  
  <pre><code>:-1: błąd:cannot find -lGL
  :-1: błąd:collect2: ld returned 1 exit status
  </code></pre>
  
  <p>When I go into Tools -> Options... I can see that it set GCC as compiler automatically and that there is some error in "manually set" (though I did not set enything). It links to: <code>/usr/bin/qmake-qt4</code>. And the error near it is: <code>No qmake or it is not an executable</code> (or something similiar, I am using Polish language for QtCreator).</p>
  
  <p>Then I decided to install <code>sudo apt-get install build-essential</code> but still nothing changed... shall I manually install qmake or something...? And what about the errors... does it has something to do with OpenGL? I am confused.</p>