title: How to point Xcode to an old SDK so it can be used as a "Base SDK"?
body: <p>My Mac's Setup:</p>
  
  <p><strong>Volume A</strong>:<br>
  OS X 10.8<br>
  Xcode 4.5 or later - 10.6 SDK <strong>IS NOT</strong> available as Base SDK<br></p>
  
  <p><strong>Volume B</strong>:<br>
  OS X 10.7<br>
  Xcode 4.3.3 - 10.6 SDK <strong>IS</strong> available as Base SDK<br></p>
  
  <p><strong>Volume C</strong>:<br>
  OS X 10.6<br>
  Xcode 4.2 - 10.6 SDK <strong>IS</strong> available as Base SDK<br></p>
  
  <hr>
  
  <p>On Volume A, I have installed Xcode 4.5, which does not include the 10.6 SDK as an available "Base SDK" in my Build Targets' Build Settings.</p>
  
  <p>I have a separate 10.6 volume and 10.7 volume on this hard drive - both of which have Xcode installed, and both of which allow me to select the 10.6 SDK as a Base SDK in my Xcode Build Targets' Build Settings.</p>
  
  <p>I know that I have the 10.6 SDK installed on Volume C (at <code>/Developer/SDKs</code> from an older Xcode installation).</p>
  
  <p>How can I point Xcode on Volume A to the 10.6 SDK which lives on Volume C?</p>