title: building Qt for Windows with msvc - Qmakespec error
body: <p>I am trying to statically build Qt using Visual Studio 2013</p>
  
  <p>To do so, I'm following <a href="http://doc.qt.io/qt-5/windows-building.html" rel="nofollow">the instructions provided by the official website</a></p>
  
  <p>1) ActivePerl 5.20 is downloaded, installed and added to the PATH.</p>
  
  <p>2) The archive for qt-everywhere-enterprise-src-5.3.1 is downloaded and unzipped in C:\Qt\Entreprise_2</p>
  
  <p>3) I open msvc 2013 command prompt, and change directory to: C:\Qt\Entreprise_2\qt-everywhere-enterprise-src-5.3.1</p>
  
  <p>4) From here, I add 2 new elements to the path:</p>
  
  <p>SET PATH=C:\Qt\Entreprise_2\qt-everywhere-enterprise-src-5.3.1\qtbase\bin;C:\Qt\Entreprise_2\qt-everywhere-enterprise-src-5.3.1\gnuwin32\bin;%PATH%</p>
  
  <p>5) I define  the QMAKESPEC in order to use msvc: SET QMAKESPEC=win32-msvc2013.</p>
  
  <p>6) finally, I launch the compilation:
  configure -commercial -nomake tests -nomake examples -debug -static</p>
  
  <p>If I skip part 5), I instead receive the </p>
  
  <p>I receive the answer:
  "QMAKESPEC environment variable is set to "win32-msvc2013" which is not a supported platform"</p>
  
  <p>If I skip step 6, I obtain instead:
  "Unable to detect the platform from environment. Use -platform commandlineargument or set the QMAKESPEC environment variable and run configure again"</p>
  
  <p>However, according to Qt support center:</p>
  
  <p>1) "win32-msvc2013" is the correct QMAKESPEC to use with Visual Studio</p>
  
  <p>2) If we use Visual Studio Command prompt (as I did) instead of the normal one, setting QMAKESPEC is optionnal anywey, as visual studio is supposed to set the correct parameters at the beginning</p>
  
  <p>So, does anyone have any idea about how I could resolve these errors?</p>
  
  <p>Incidentally does anyone knows what defines a Qmakespec as corresponding to a "supported platform"?</p>