title: Pod Spec Lint CoreSimulator detected Xcode.app relocation or CoreSimulatorService version change
body: <p>The command <code>pod spec lint</code> fails. I couldn't find a similar question here on SO and on Cocoapod's repo. Full log:</p>
  
  <blockquote>
    <p>-> GPKit (0.1.1)
        - ERROR | [iOS] unknown: Encountered an unknown error (757: unexpected token at '2017-08-17 16:12:08.932 simctl[55281:678990]
    CoreSimulator detected Xcode.app relocation or CoreSimulatorService
    version change.  Framework path
    (/Applications/Xcode.app/Contents/Developer/Library/PrivateFrameworks/CoreSimulator.framework)
    and version (375.21) does not match existing job path
    (/Library/Developer/PrivateFrameworks/CoreSimulator.framework/Versions/A/XPCServices/com.apple.CoreSimulator.CoreSimulatorService.xpc)
    and version (459.13).  Attempting to remove the stale service in order
    to add the expected version. ') during validation.</p>
    
    <p>Analyzed 1 podspec.</p>
    
    <p>[!] The spec did not pass validation, due to 1 error.</p>
  </blockquote>
  
  <p>Any solution for this? And why it happens?</p>