title: Xcode 7.3 library project compiles every time
body: <p>I have a library project that used to build just fine in Xcode 7.2. If I just compiled it, it would rebuild it on subsequent builds. After upgrading to Xcode 7.3, Xcode recompiles all the files on every build even if I make no changes to any file. </p>
  
  <p>I did a deep clean and also deleted the derived data folder to make sure that was not the cause. The dependent library projects build fine (they don't recompile everything) when I compile them independently. I have looked through all the settings but couldn't figure out why this is happening.</p>
  
  <p>I stumbled upon 2 things that "fixed" the problem but I don't want to use any of these "solutions"</p>
  
  <ol>
  <li><p>I changed the Optimization Level (for LLVM) from None [-O0] to Fastest, Smallest [-Os] and that did the trick. Im not sure why without the optimization it recompiled all the files, all the time (even if it was not changed).</p></li>
  <li><p>I have a pre-processor flag (DEBUG=1) for debug builds and if I remove that flag then it stops recompiling all the files, all the time </p></li>
  </ol>
  
  <p>The above 2 options don't work for me.</p>
  
  <p>Has anyone seen similar behavior?</p>