I tried to reproduce your problem, but was unable to. I installed Rails 3.1.3, Warbler 1.4.0.beta2, and JRuby 1.7.6. After creating a new Rails application, I created a controller / view, precompiled my assets, then created a war by running warble
. I then dumped my WAR into Jetty 9.0.6 (v20130930).
I was able to navigate to the application and plenty of files are located in the WAR at WEB-INF/gems/gems/activesupport-3.1.3
(253 in all).
Do you have a custom warbler file that might be changing how you build your WAR? Perhaps you can remove it and try "stock" warbler configs.