title: How do I set a previous base SDK in Xcode 10?
body: <p>In earlier versions of Xcode I could set the base SDK to the current iOS version and the deployment target to an earlier version as shown in the below slide from the iOS 7 TechTalk, session Architecting Modern Apps, Part 2:</p>
  
  <p><a href="https://i.stack.imgur.com/7nwlt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7nwlt.png" alt="iOS 7 TechTalk, session Architecting Modern Apps, Part 2"></a></p>
  
  <p>This Stack Overflow question elaborates nicely on the Base SDK vs Deployment target.</p>
  
  <p><a href="https://stackoverflow.com/questions/18568572/whats-the-meaning-of-base-sdk-ios-deployment-target-target-and-project-in-xc">What&#39;s the meaning of Base SDK, iOS deployment target, Target, and Project in xcode</a></p>
  
  <p>However, now when I look at the base SDK config field in Xcode I just see "iOS" (which is an alias of "iphoneos").</p>
  
  <p>According to <a href="https://developer.apple.com/ios/submit/" rel="noreferrer">https://developer.apple.com/ios/submit/</a></p>
  
  <blockquote>
    <p>Starting March 2019, all iOS apps submitted to the App Store will need
    to be built with the iOS 12.1 SDK or later, and support the all-screen
    design of iPhone XS Max or the 12.9-inch iPad Pro (3rd generation).</p>
  </blockquote>
  
  <p>This worries me because it seems that I can no longer target older versions of iOS.</p>
  
  <p>I've done a lot of research by I cannot seem to work out definitively whether there still a way to use the 12.1 SDK but target older versions of iOS. Is there a way to do this?</p>