title: Qt 5 migration - Cannot open include file: 'ui_mainwindow.h'
body: <p>I'm trying to migrate a simple project to Qt 5. The project was originally written for Qt 4, and it compiles fine there.</p>
  
  <p>When compiling with Qt 5, however, I'm getting this error:</p>
  
  <pre><code>error: C1083: Cannot open include file: 'ui_mainwindow.h': No such file or directory
  </code></pre>
  
  <p>Now I know that ui_mainwindow.h should be auto-generated when compiling, and I've checked and it is not being generated when compiling with Qt 5.</p>
  
  <hr>
  
  <p><strong>Note</strong></p>
  
  <p>This happens on a newly created project as well.</p>
  
  <p>Steps to reproduce:</p>
  
  <ol>
  <li>Create new project under Qt Creator + Qt 4.</li>
  <li>Copy project to another machine where Qt Creator + Qt 5 has been installed.</li>
  <li>Open project, after fixing some initial errors this one pops up.</li>
  </ol>