In the test,

*.extensions.observer.broken.definitionError.ProcessObserverMethodErrorTest

there's a EventB class and an extension class ProcessObserverMethodObserver with an observer method for EventB. In that method, there is a call to,

event.addDefinition(...)

which is expected to trigger a deployment error in the test. However, AFAICT the observer method is never called because EventB is never fired, resulting in the deployment to succeed and the test to fail.