Forum: JRuby Warbler JAR with Rails models

I've been experimenting with creating an executable jar that runs a Ruby
script that depends on Rails models.  I created an empty Rails app to
play with at http://github.com/slumos/warbler-testapp.  The challenge is
to execute bin/testapp, which loads the Rails environment.

To start, I had to do some hacking to override Rails detection in
config/warble.rb:

# Override the Rails detection
Warbler.framework_detection = false
Warbler::Traits.module_eval do
  def auto_detect_traits
    [Warbler::Traits::Bundler, Warbler::Traits::Jar, 
Warbler::Traits::NoGemspec]
  end
end

This seemed almost to work, but then after successfully loading a dozen
gems, it blows up with a LoadError for bundle/index.  I successfully
eliminated the dependency on Bundler by setting

ENV['BUNDLE_GEMFILE'] = ''

in bin/testapp.  But now I have no idea what to do with this:

Errno::ENOENT: No such file or directory - 
/private/tmp/jar/jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/locale/en.yml
             mtime at org/jruby/RubyFile.java:890
        updated_at at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/file_update_checker.rb:100
               map at org/jruby/RubyArray.java:2361
        updated_at at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/file_update_checker.rb:100
           execute at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/file_update_checker.rb:77
   initialize_i18n at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/i18n_railtie.rb:67
           Railtie at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/i18n_railtie.rb:34
              call at org/jruby/RubyProc.java:249      execute_hook at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/lazy_load_hooks.rb:34
    run_load_hooks at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/lazy_load_hooks.rb:43
              each at org/jruby/RubyArray.java:1613
    run_load_hooks at 
jar:file:/private/tmp/jar/testapp.jar!/gems/activesupport-3.2.12/lib/active_support/lazy_load_hooks.rb:42
          Finisher at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/application/finisher.rb:59
     instance_exec at org/jruby/RubyBasicObject.java:1720
               run at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/initializable.rb:30
  run_initializers at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/initializable.rb:55
              each at org/jruby/RubyArray.java:1613
  run_initializers at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/initializable.rb:54
       initialize! at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/application.rb:136
          __send__ at org/jruby/RubyBasicObject.java:1659
              send at org/jruby/RubyKernel.java:2086
    method_missing at 
jar:file:/private/tmp/jar/testapp.jar!/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30
            (root) at 
file:/private/tmp/jar/testapp.jar!/testapp/config/environment.rb:5
           require at org/jruby/RubyKernel.java:1027
            (root) at 
jar:file:/var/folders/fj/5jjtp7hd7673q5_h4cl02r580009tv/T/jruby7518566963929780211extract/jruby-stdlib-1.7.2.jar!/META-INF/jruby.home/lib/ruby/shared/rubygems/custom_require.rb:1
           require at 
jar:file:/var/folders/fj/5jjtp7hd7673q5_h4cl02r580009tv/T/jruby7518566963929780211extract/jruby-stdlib-1.7.2.jar!/META-INF/jruby.home/lib/ruby/shared/rubygems/custom_require.rb:36
              load at org/jruby/RubyKernel.java:1046
            (root) at 
file:/private/tmp/jar/testapp.jar!/testapp/bin/testapp:7
           require at org/jruby/RubyKernel.java:1027
            (root) at 
file:/private/tmp/jar/testapp.jar!/META-INF/main.rb:1
            (root) at 
file:/private/tmp/jar/testapp.jar!/META-INF/main.rb:1

My Java-fu is not super-strong.  Is this business of gems attempting to
open files in relative to their own location simply incompatible with
running from a jar? Or is it an incompatibility between warbler and
certain rubygems versions like my googling suggests? I started with and
want to use jruby-1.7.2, but also have tried multiple versions back to
jruby-1.6.3 and rubygems-1.5.1 with identical results.

Can anyone suggest a way forward?

Thanks in advance.

Steven