We use Microsoft Fakes to isolate some legacy code. Today I added some tests that passed on my machine, but failed on the buildserver. 😦

After reading this stackoverflow post I added the

using(ShimsContext.Create()) {
   var fakeObject = new some.namespace.Fakes.LegacyObject();
   fakeObject.BehaveAsDefaultValue();
   // ... rest of test
}

and the builds became green again 😉