title: (Qt 5.4.1) This application failed to start because it could not find or load the Qt platform plugin "xcb"
body: <p>I reinstalled my ubuntu 14.04 and Qt 5.4.1 and Qtcreator.</p>
  
  <p>Qt 5.4.1 was built from source with "-opensource -nomake-test -nomake-example" configure options.</p>
  
  <p>When I open an old project in QtCreator and build it everything's OK.</p>
  
  <p>But when I run this project it shows:</p>
  
  <blockquote>
    <p>This application failed to start because it could not find or load the Qt platform plugin "xcb".</p>
    
    <p>Available platform plugins are: linuxfb, minimal, offscreen, xcb.</p>
    
    <p>Reinstalling the application may fix this problem. 
    Aborted (core dumped)</p>
  </blockquote>
  
  <p>So I googled this problem and tried everything.
  I installed every packages (libxcb series) but nothing can help!</p>
  
  <p>Somebody help me please...</p>
  
  <p>I tried your methods.</p>
  
  <p>When I run <code>ldd</code> command in <code>platform</code> directory, It shows:
  <img src="https://i.stack.imgur.com/JLGON.jpg" alt="ldd libqxcb.so under platform$"></p>
  
  <p>You can see that nothing is missing. And actually I have made a softlink in the platform directory called libqxcb.so. There was no libqxcb.so in my platform directory before.</p>
  
  <p>And when I run <code>ldd</code> command to my executable. it shows:
  <img src="https://i.stack.imgur.com/1uls8.jpg" alt="executable shot"></p>
  
  <p>And you can see the error when I execute this file.</p>