title: Xcode Server Bot, ipatool error
body: <p>We have an Xcode Server bot set up for CI for our project, using Xcode 7.1. It's set to produce an IPA. We only recently noticed, but a few weeks ago, it started giving this warning every build:</p>
  
  <blockquote>
    <p>Bot Issue for CareConsult Bot (develop) (build service warning)
    Assertion: exportArchive: ipatool failed with an exception:</p>
    
    <h1></h1>
    
    <p>File: (null):(null)</p>
  </blockquote>
  
  <p>This prevents it from producing an IPA, which is a problem.</p>
  
  <p>I've tried:
  - Creating a new bot
  - updating gems (saw a similar issue that was resolved this way)</p>
  
  <p>Doing an archive &amp; export on my local machine gives the same error if I choose to "Export for specific device". So the problem is not specific to the build server.</p>
  
  <p>Any ideas?</p>