title: How to set compiler flags in Compile Sources to omit a file from a build configuration
body: <p>I want to set the Debug flag in Compile Sources. But I'm not sure what the right way is. I don't want to compile some files when I'm building for release.<br/></p>
  
  <p>Other Swift Flags screenShot:</p>
  
  <p><a href="https://i.stack.imgur.com/KyrMZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KyrMZ.png" alt="Other Swift Flags screenShot"></a></p>
  
  <p>Compile Sources screenShot:</p>
  
  <p><a href="https://i.stack.imgur.com/iIzxG.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iIzxG.jpg" alt="Compile Sources screenShot"></a></p>