title: Xcode 10 fails my tests in simulator without any information as to the failure
body: <p>Since upgrading to Xcode 10 my tests (which before the upgrade passed) are no longer being run as far as I can tell.  The build succeeds, then the tests fail, but there is no report to say why.</p>
  
  <p>Originally my target OS was 10.3, but I noticed a greyed out iOS11 in the settings, I have since reverted this to 10.3 with no change.</p>
  
  <p>I have restarted my machine and this doesn't seemed to have helped.</p>
  
  <p>Any insight would be helpful.</p>
  
  <p>I do note that this is the inverse of the problem reported <a href="https://stackoverflow.com/questions/52395320/xcode-10-fails-to-run-xctest-xcuitest-on-device">here</a></p>
  
  <p>Thanks</p>