Scala on Google App Engine with Eclipse

I'm trying to create web app on pure Scala code. I use last version of Goo开发者_StackOverflow中文版gle plugin for Eclipse to create App Engine Web project. After it I add Scala nature to project. I rewrite standart Java servlet generated by Google plugin to Scala servlet version. Everything fine, no scala code errors found. But Eclipse show me some errors in my Scala servlet code like this:

Unexpected error while validating ScalaServlet.scala.

This error generated by com.google.appengine.eclipse.core plugin. I can't understand, where I can fix this error ?

In the project Properties -> Builders, move Scala Builder to top of the list

Given the lack of threading support, GAE isn't the best place for Scala code.

I'd recommend you check out Stax: http://www.stax.net/

Amongst other features, they let you build/deploy with Maven, so you're not forced into the non-standard directory layout that Google's eclipse plugins so frequently insist upon.

They also use scala internally, and seem very willing to help out with scala-related issues.