Xcode 9.4 : Error generating code coverage

Question

I'm running all test cases of project (cmd + U) then all of sudden this error message pops-up with no reason. I'm using Xcode 9.4.

Any fix?

Answer 1

Is is possible you are running on device and it is locked?

The same thing just happened for me ("Error Generating Code Coverage" when trying to run all tests) and then I realized that Xcode was trying to build to my phone, which was locked. It ran ok on my phone after I unlocked it (and fine on the simulator as well).

Answer 2

I also had this problem and was able to solve it by running on a simulator rather than on my iPhone. If that doesn't work for you, look in the Report navigator (look for this button: ) I had a failing Build Log in there with a message like this:

Test target MyAppTests encountered an error (Unable to connect to test manager on xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx If you believe this error represents a bug, please attach the log file at /var/folders/…filename.log)

If you have a message like that, take a look at the log file… it's what made me realise it was trying to connect to my iPhone.