Simple jar built with warbler works in 1.6.7, breaks in 1.7 with require 'haml'

I'm not sure if this belongs here, but I'm not sure where else to put it. Seems like it's related to upgrading to 1.7 from 1.6.7. I have a simple project set up with warbler to compile a jar. Simply requiring haml seems to break the jar, but I can't see anything wrong with the require that comes from haml.

bin/test.rb:

require 'haml'

Gemfile:

source "http://rubygems.org"

gem 'warbler'
gem 'haml'

config/warble.rb:

Warbler::Config.new do |config|
config.features = %w(compiled)
config.dirs = %w(bin)
config.java_libs = FileList["ext/*.jar"]
end

ext/jruby-complete.jar <- newly built jar from jruby master

I've also attached this as a zip, but without the jruby jar. I create the jar with: bundle exec warble compiled jar. Using 1.6.7, this jar starts fine. In jruby 1.7, starting the jar results in:

bporterfield@ ~/dev/jar_test$ ruby -v
jruby 1.7.0.dev (ruby-1.9.3-p139) (2012-03-29 4972b84) (OpenJDK 64-Bit Server VM 1.7.0-u4-b228) [darwin-amd64-java]
bporterfield@ ~/dev/jar_test$ java -jar jar_test.jar
Errno::ENOENT: No such file or directory - jar:file:/Users/bporterfield/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/VERSION
initialize at org/jruby/RubyFile.java:501
open at org/jruby/RubyIO.java:1099
open at org/jruby/RubyKernel.java:295
read at org/jruby/RubyIO.java:3500
read at org/jruby/RubyIO.java:3597
version at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml/version.rb:45
Haml at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml/version.rb:108
(root) at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml/version.rb:3
require at org/jruby/RubyKernel.java:991
require at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml/version.rb:36
(root) at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml.rb:4
require at org/jruby/RubyKernel.java:991
require at jar:file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/gems/haml-3.1.4/lib/haml.rb:59
(root) at bin/test.rb:1
load at org/jruby/RubyKernel.java:1017
(root) at file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/META-INF/main.rb:1
require at org/jruby/RubyKernel.java:991
require at file:/Users/bporterfield/Dropbox/dev/jar_test/jar_test.jar!/META-INF/main.rb:36