title: How can I fix this build error when building Qt 5.7 statically with MinGW?
body: <p>When I tried to compile <code>Qt 5.7</code> statically in order to get a standalone application for windows deployment with all dependencies as mentionned <a href="http://doc.qt.io/qt-5/windows-deployment.html" rel="nofollow">here</a> i got the following errors:</p>
  
  <blockquote>
    <p>C:\Qt\Qt5.7.0\5.7\Src\qtbase/qmake/library/qmakebuiltins.cpp: In member function 'QByteArray QMakeEvaluator::getCommandOutput(const QString&amp;) const'</p>
    
    <p>C:\Qt\Qt5.7.0\5.7\Src\qtbase/qmake/library/qmakebuiltins.cpp:419:94: error: '_popen' was not declared in this scope
                                    + QLatin1String(" &amp;&amp; ") + args).toLocal8Bit().constData(), "r")) {</p>
    
    <p>C:\Qt\Qt5.7.0\5.7\Src\qtbase/qmake/library/qmakebuiltins.cpp:427:23: error: '_pclose' was not declared in this scope
             QT_PCLOSE(proc);</p>
    
    <p>Makefile:204: recipe for target 'qmakebuiltins.o' failed
    mingw32-make: *** [qmakebuiltins.o] Error 1
    Building qmake failed, return code 2</p>
  </blockquote>
  
  <p>My aim is to make the final release standalone and size optimized (only ncessary symbols that being used from the libs), also in the link i provided i don't see <code>MinGw</code> mentionned, I don't have <code>nmake</code> (and don't want to get it).</p>