When I run tests on my project in XCode, it builds, and then says Testing... which never ends.
When I use the stop button, the process stops with this text in the console:
*** If you believe this error represents a bug, please attach the log file at /Users/MY.NAME/Library/Developer/Xcode/DerivedData/APPNAME-gcsubmsjksdbljcswbefkgugjray/Logs/Test/C53D8988-3564-4C2B-A535-075D26D1E4A7/Session-APPNAMETests-2016-07-13_140704-t3DFd5.log
However, I am unable to run the tests again, and have to relaunch xcode to run them.
Is this an issue on XCode that may be known to the Apple developers?
EDIT
So, I figured, the simulator is not launching in time, and that fails the xcode to run the tests. It might be an installation bug with the simulator.
As I anticipated in my edit to the question the first time, XCode installation did not install the simulator correctly. I trashed the old installed version and reinstalled XCode. And now everything works fine.
Thanks for all the help.