title: Xcode, Duplicate symbol _main
body: <p>I have duplicate symbol _main.</p>
  
  <p>The problem is it says "Duplicate symbol _main in /Users/.../i386/main-B9843B6026D6EFA4.o and /Users/.../i386/main-B9843B6026D6EFA4.o", the XXX and XXX are actually the same .o file. I don't know why it thinks it's duplicate symbol when it's the same .o?!</p>
  
  <p>Any help appreciated, thanks.</p>