I’m trying to use the hbm2ddl nant task to generate my database schema, however I’m running into a problem where this exception is being thrown:
I found two JIRA issues concerning this problem: NH-952 and NH-652. They say its been fixed, but perhaps the hbm2ddl nant task needs to be somehow updated?

I tried reordering my mapping files by renaming them so the classes higher in the class hierarchy occur first alphabetically. But this didn’t have any effect. I think I also need to pass skipOrdering=true to the Configuration.AddAssembly method. How can I do that via the hbm2ddl nant build file?

Just now I upgraded from NHibernate version 1.2.0.GA to the latest version which is 1.2.1.GA. The problem is now gone. Oops... guess I should have upgraded earlier.