title: Qt Creator: “XYZ does not name a type”
body: <p>This is a very frustrating error message in Qt Creator:  <code>’XYZ’ does not name a type</code>.  This usually means that there is an error in the class <code>XYZ</code> that prevents the compiler from generating the type, but there are no additional hints as to what went wrong.</p>
  
  <p>Any suggestions?</p>