Segmentation fault 11 when code coverage is turned on in Swift

问题

While I am running unit tests with XCTest in Swift, they run fine when code coverage is turned off. However once I try to enable code coverage, I have a failed build/test with 4 classes giving the following error message: Command failed due to signal: Segmentation fault: 11.

回答1:

Here is what worked for me (as all the other suggestions did not work in my case). I was getting a segmentation fault 11 on a particular Swift class when trying to run unit tests with code coverage turned ON. It turns out that we had a ternary expression on a class's property like so:

let cellBorder : CGFloat = MyHelperClass.isIPad() ? 10.0 : 6.0

Making it a lazy var fixed the problem:

lazy var cellBorder : CGFloat = MyHelperClass.isIPad() ? 10.0 : 6.0

To be clear, the code compiled and worked fine until we tried turning on code coverage. I also found this Open Radar and this guy's post that outlined the solution. Appears to be an Apple bug.

回答2:

Without code, build settings, etc. it's hard to say for sure but one thing you should check is to make sure that you are using a @testable import flag in your unit test classes.

For instance with a project named MyApp at the top of your unit test class you would include with the following import @testable import MyApp.

You also want to check to ensure that you've followed the process for enabling coverage all the way through. That information is documented on Apple's developer portal:

Code Coverage | Apple Developer