How to turn datamodel into a versioned datamodel in Xcode4?

I remember that in Xcode 3.x you could simply Add Model Version and Xcode would convert your datamodel into a versioned datamodel. For some reason when I try doing so following the same steps in Xcode4, it crashes the environment and doesn't 开发者_开发技巧make any of the desired changes.

Does anyone know the right steps on versioning and migrating your datamodel in Xcode4?

I just found this previous question and commented on it. I believe it's the same bug and they haven't fixed it yet.

Choose Editor > Convert to Versioned Model to convert a data model to a versioned data model.