title: Qt error when setting the application icon
body: <p>I am trying to set the application icon with Qt on windows7. I follow every step as the Qt document says. But I got the error message: </p>
  
  <pre><code>mingw32-make[1]: *** [release/Makenotepad_resource_res.o] Error 1
  </code></pre>
  
  <p>I put the compiler output:</p>
  
  <pre><code>&gt;13:15:35: Running steps for project Makenotepad...
  13:15:35: Configuration unchanged, skipping qmake step.
  13:15:35: Starting: "C:\Qt\Qt5.7.0\Tools\mingw530_32\bin\mingw32-make.exe" 
  C:/Qt/Qt5.7.0/Tools/mingw530_32/bin/mingw32-make -f Makefile.Release
  mingw32-make[1]: Entering directory 'C:/Qt/build-Makenotepad'
  windres -i "..\Saved project\Makenotepad\myapp.rc" -o release\myapp_res.o --include-dir=./"../Saved project/Makenotepad" -DUNICODE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN
  windres: can't popen `gcc -E -xc -DRC_INVOKED -I./../Saved\ project/Makenotepad -DUNICODE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN "..\Saved project\Makenotepad\myapp.rc"': No error
  Makefile.Release:68: recipe for target 'release/myapp_res.o' failed
  mingw32-make[1]: Leaving directory 'C:/Qt/build-Makenotepad'
  mingw32-make[1]: *** [release/myapp_res.o] Error 1
  Makefile:34: recipe for target 'release' failed
  mingw32-make: *** [release] Error 2
  13:15:36: The process "C:\Qt\Qt5.7.0\Tools\mingw530_32\bin\mingw32-make.exe" exited with code 2.
  Error while building/deploying project Makenotepad (kit: Desktop Qt 5.7.0 MinGW 32bit)
  When executing step "Make"
  13:15:36: Elapsed time: 00:01.
  </code></pre>
  
  <p>I have been searching for this issue for half days already, actually, there are many people has the same issues, and there is no clear answers for it. Can someone please help, thanks.</p>