Keep Coding

I have been playing around with spring roo for some time now, read most of the documentation, tried most of the tutorials I could find (pizze, wedding...) - all worked well. My next step was to create a basic application, that can be deployed on Google App Engine. I just can't get it to work.
I found a simple tutorial that consists of 2 Entities and seems to run fine on GAE. It has been created using Roo-1.1.0.M2. I did the exact same steps but could not get it to run. I tried Roo-1.1.0.RELEASE as well as the current Roo-1.1.1 development branch. I always ran into the same problem as Ron.
I was able to strip down the test.roo file to
project --topLevelPackage com.springsource.failureexample
persistence setup --provider DATANUCLEUS --database GOOGLE_APP_ENGINE --applicationId failureexample
entity --class ~.domain.Person --testAutomatically
perform tests
Using this example, I get something like ERROR DataNucleus.Transaction - Operation rollback failed on resource: org.datanucleus.store.appengine.DatastoreXAResource and the build fails with a test in testCountPeople(com.springsource.failureexample.domain.PersonIntegrationTest).
The problem is also described at Roo's issue tracker (where I provided my minimal test script), but since it obviously worked at other setup, I might have misunderstood or overlooked something important in the setup process.
Could you provide some ideas of what my error might be?

How about creating at least one field in your entity ?