title: Upgrade QT 5.4 or Qt 5.5 - Install and run - Ubuntu 14 and 15
body: <p>I have searched all day in order to use Qt 5.4 or Qt 5.5.
  I have two machines, one running Ubuntu 15 and the other Ubuntu 14, but got the same results.
  I have installed the program through the download-online package, and now I have beautiful <code>/opt/Qt/5.4/</code> and <code>/opt/Qt/5.5</code> folders.</p>
  
  <p>That's all. I am stuck in here. If I run <code>qmake -version</code>, the reply is:</p>
  
  <pre><code>Using Qt version 5.2.1 in /usr/lib/x86_64-linux-gnu
  </code></pre>
  
  <p>Also, if I run <code>qtchooser -list-versions</code>, I get:</p>
  
  <pre><code>4
  5
  default
  qt4-x86_64 linux-gnu
  qt4
  qt5-x86_64 linux-gnu
  qt5
  </code></pre>
  
  <p>I have to use SuperCollider 3.7 for an important project, and I need Q t5.4 or higher. Is there anybody who can tell me what to do after installing the package to make programs see Qt 5.4 or higher?</p>
  
  <p>I even tried to build from the source code, but in that case init-repository doesn't work.</p>
  
  <p>Luca</p>