title: Why do I get this "error: undefined reference to `qt_version_tag' "?
body: <p>I am using Qt 5.7 on Ubuntu 16 LTS machine.</p>
  
  <p>I get this error:</p>
  
  <blockquote>
    <p>(.qtversion[qt_version_tag]+0x0):-1: error: undefined reference to `qt_version_tag'</p>
  </blockquote>
  
  <p>This error comes only when I use SDL libraries.</p>