Code coverage reporting seems to be off in Xcode 9

We've noticed in our project that the reported summary coverage does not seem to reflect the actual coverage. For instance we've got unit tests covering API endpoint and while the coverage side bar shows that these lines have been hit (and we know they do, from running the tests), the build log insists some files have zero coverage.


Interestingly, this is not a problem for all files, just for some.


The project is in Swift 4 and includes unit tests and UI tests. Both cover the method in question but even when running only one of the test suites, these files do not show coverage. So it doesn't seem to be related to those test runs interfereing with each other.


Has anyone seen similar issues? Is there any project setting we're missing? (Enable Code Coverage Support is Yes)


https://www.dropbox.com/s/bgau2m28tafabey/Screen%20Shot%202017-10-02%20at%2010.23.14.png?dl=0


Code coverage reporting seems to be off in Xcode 9
 
 
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