Domain Error = IDETestOperationsObserverErrorDomain Code = 12 "Failed to run background test runner"

Question

I run xcodebuild testfor testing ui test. Performing Jenkins assignments.

Repeating this problem over and over again

xcodebuild [8028: 16918138] Error Domain = IDETestOperationsObserverErrorDomain Code = 12 "Failed background test runner.

Testing failed: the MyAppUITests test object detected an error (The background test failed to start. If you think this error is an error, attach the log file to / Users / Shared / Jenkins / Home / workspace / ***. Log)

** FAILURE TEST **

I did not find anything in the location of the log.