Sharing tests between developers using Xcode, what's going on?

In Xcode 6.2 I created a test target called CommonTests:

and wrote some tests in it that are all passing on my machine:

I marked the scheme as shared so other developers could easily run them:

Another developer tried to run them and got an error that I don't understand yet, but in the investigation, we discovered his Xcode is seeing the test target quite differently than mine:

Any ideas what's going on? Anything we can delete for Xcode to refresh the known tests from the code and shared scheme?