The first build was successful, but it didn’t run the unit tests. The build log contained the following warning:
No test found. Make sure that installed test discoverers & executors, platform & framework version settings are appropriate and try again.Of course, I was missing the NUnit test adapter on the build server. The article on how to Run tests in your build documents how to resolve this in the Q/A section — but that solution involves checking in binaries and tweaking your build definition. I’m not a big fan of that approach and fortunately there’s another way to solve this.