title: qmake missing object file
body: <p>Alright... So I am very new to Qt. I just installed it on my Ubuntu distribution.
  I created a new test application to see if it worked with the following file (helloworld.cpp) in my ../helloworld/ directory:</p>
  
  <pre><code>/*  helloworld.cpp */
  #include &lt;QApplication&gt;
  #include &lt;QWidget&gt;
  
  int main(int argc, char *argv[])
  {
      QApplication app(argc, argv);
  
      QWidget window;
  
      window.resize(250, 150);
      window.setWindowTitle("Simple example");
      window.show();
  
      return app.exec();
  }
  </code></pre>
  
  <p>and I ran <code>qmake -project</code> in order to generate the helloworld.pro file.
  Next I ran <code>qmake</code> in order to genereate the Makefile
  Next I ran <code>make</code> in order to compile and got the following output/error:</p>
  
  <pre><code>g++ -c -m64 -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG 
  -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/share/qt4/mkspecs/linux-g++-64 -I. 
  -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 
  -I. -I. -o helloworld.o helloworld.cpp
  helloworld.cpp:1:24: fatal error: QApplication: No such file or directory
  compilation terminated.
  make: *** [helloworld.o] Error 1
  </code></pre>
  
  <p>meaning the helloworld.o file is missing... How do I fix this? I tried adding <code>QT += webkit</code> as another discussion said... and that didn't work either.</p>
  
  <p>Any code monkeys out there have any ideas how to fix this??? I would greatly appreciate it!</p>