The Spec suite is currently exhibiting issues, when run under Ruby 1.8.7. Ruby 1.8.7 interpreters MRI, JRuby, and Rubinius should all be tested and verified as working.
In addition, it would make sense to use something like RVM, on the CI server, so we can easily test compatibility across different Ruby versions and interpreters.
This does not affect Ruby-1.9.2 MRI, and has not been tested under JRuby's 1.9 mode. CI should run JRuby twice, under both the 1.8 and 1.9 compatibility-modes.