title: After switching to Xcode 7, app size grew from 9 MB to 60 MB, is there a fix?
body: <p>I've been going backwards in Git history to find the cause of a humongous file size change, but the only real reason I can find is the switch from Xcode 6 to Xcode 7 GM.</p>
  
  <p>I've found that these are the top 10 file size contributors in an <code>.ipa</code> created from the <em>Archive</em> operation on a <em>Release</em> build configuration:</p>
  
  <pre><code>$ unzip -lv Roger\ Release.ipa | sort -k +3nr | head
  41802768  Defl:N 16887199  60%  09-14-15 23:47  dc24cdc1  Payload/Roger.app/Frameworks/libswiftCore.dylib
  41802400  Defl:N 16886076  60%  09-06-15 18:33  f939ea6a  SwiftSupport/iphoneos/libswiftCore.dylib
  11184032  Defl:N  5915625  47%  09-14-15 23:48  6ceac4a2  Payload/Roger.app/Roger
   6399584  Defl:N  2670275  58%  09-14-15 23:47  0ac52d3f  Payload/Roger.app/Frameworks/libPhoneNumber_iOS.framework/libPhoneNumber_iOS
   5410384  Defl:N  2334189  57%  09-14-15 23:47  7a8cb03f  Payload/Roger.app/Frameworks/Alamofire.framework/Alamofire
   4521904  Defl:N  2292789  49%  09-14-15 23:47  95da0882  Payload/Roger.app/Frameworks/FBSDKCoreKit.framework/FBSDKCoreKit
   4731552  Defl:N  1926357  59%  09-14-15 23:48  e05337de  Payload/Roger.app/Frameworks/libswiftFoundation.dylib
   4731168  Defl:N  1925355  59%  09-06-15 18:33  19a5c3c4  SwiftSupport/iphoneos/libswiftFoundation.dylib
   2659232  Defl:N  1232897  54%  09-14-15 23:47  1a53a401  Payload/Roger.app/Frameworks/AFNetworking.framework/AFNetworking
   1196624  Defl:N   545343  54%  09-14-15 23:47  19a063cb  Payload/Roger.app/Frameworks/Bolts.framework/Bolts
  </code></pre>
  
  <p>By far the largest files are the two (slightly different) <code>libswiftCore.dylib</code> files, which total over 32 MB. In the bundle built by Xcode 6 these two files totaled only 3 MB.</p>
  
  <p>So question #1 is: Why are the Swift core files there twice? (<strong>Embedded Content Contains Swift Code</strong> is set to <em>No</em>).</p>
  
  <p>And question #2 is: What happened? Why did the Swift core size increase by 15 MB? Is this permanent?</p>
  
  <p>Some additional notes:</p>
  
  <ul>
  <li>This is a project that was entirely Objective-C but is now mostly Swift. The <strong>Defines Module</strong> setting is set to <em>Yes</em>.</li>
  <li>The project uses CocoaPods with <code>use_frameworks!</code> set.</li>
  <li>I've confirmed the actual download size from TestFlight on multiple devices and iOS versions and it's in the range 30–60 MB (presumably the difference is due to app slicing). It used to be 9 MB.</li>
  </ul>