bug in vegas 0.1.4, ruby 1.8.6

bug.txt

# bundler and rvm aren't relevant to the bug.  they are only used to demonstrate ruby 1.8.6 and a limited set of installed gems
== (nick@arrakis)   [Tue Mar 09]-(15:38:52) ==
~/src/sketches/vegas-bug $ rvm info
rvm 0.0.86 by Wayne E. Seguin (wayneeseguin@gmail.com) [http://rvm.beginrescueend.com/]

system:
  uname: "Linux arrakis 2.6.31-19-generic #56-Ubuntu SMP Thu Jan 28 01:26:53 UTC 2010 i686 GNU/Linux"

ruby:
  interpreter:  "ruby"
  version:      "1.8.6"
  date:         "2009-08-04"
  platform:     "i686-linux"
  patchlevel:   "2009-08-04 patchlevel 383"
  full_version: "ruby 1.8.6 (2009-08-04 patchlevel 383) [i686-linux]"

homes:
  gem:          "/home/nick/.rvm/gems/ruby/1.8.6"
  ruby:         "/home/nick/.rvm/ruby-1.8.6-p383"

binaries:
  ruby:         "/home/nick/.rvm/ruby-1.8.6-p383/bin/ruby"
  irb:          "/home/nick/.rvm/ruby-1.8.6-p383/bin/irb"
  gem:          "/home/nick/.rvm/ruby-1.8.6-p383/bin/gem"
  rake:         "/home/nick/.rvm/ruby-1.8.6-p383/bin/rake"

environment:
  GEM_HOME:     "/home/nick/.rvm/gems/ruby/1.8.6"
  MY_RUBY_HOME: "/home/nick/.rvm/ruby-1.8.6-p383"
  IRBRC:        "/home/nick/.rvm/ruby-1.8.6-p383/.irbrc"
== (nick@arrakis)   [Tue Mar 09]-(15:38:55) ==
~/src/sketches/vegas-bug $ bundle install
Fetching source index from http://gemcutter.org/
Resolving dependencies
Installing cgi_multipart_eof_fix (2.5.0) from system gems 
Installing daemons (1.0.10) from system gems 
Installing fastthread (1.0.7) from system gems 
Installing gem_plugin (0.2.3) from system gems 
Installing mongrel (1.1.5) from system gems 
Installing rack (1.1.0) from system gems 
Installing vegas (0.1.4) from rubygems repository at http://gemcutter.org/ 
Your bundle is complete!
== (nick@arrakis)   [Tue Mar 09]-(15:39:09) ==
~/src/sketches/vegas-bug $ bundle exec ./myapp.rb -F
/home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler/thin.rb:1:in `require': no such file to load -- thin (LoadError)
        from /home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler/thin.rb:1
        from /home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler.rb:17:in `const_get'
        from /home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler.rb:17:in `get'
        from /home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler.rb:17:in `each'
        from /home/nick/.rvm/gems/ruby/1.8.6/gems/rack-1.1.0/lib/rack/handler.rb:17:in `get'
        from /home/nick/.bundle/ruby/1.8/gems/vegas-0.1.4/lib/vegas/runner.rb:257:in `setup_rack_handler'
        from /home/nick/.bundle/ruby/1.8/gems/vegas-0.1.4/lib/vegas/runner.rb:255:in `each'
        from /home/nick/.bundle/ruby/1.8/gems/vegas-0.1.4/lib/vegas/runner.rb:255:in `setup_rack_handler'
        from /home/nick/.bundle/ruby/1.8/gems/vegas-0.1.4/lib/vegas/runner.rb:35:in `initialize'
        from ./myapp.rb:13:in `new'
        from ./myapp.rb:13

Gemfile

source :rubygems
gem "vegas", "~> 0.1.4"
gem "rack", "~> 1.1.0"
gem "mongrel", "~> 1.1.5"

myapp.rb

#!/usr/bin/env ruby

require 'vegas'

app = Proc.new {|env| 
  [200, {'Content-Type' => 'text/plain'}, ["This is an app. #{env.inspect}"]]
}

def app.server
  ["thin", "mongrel"]
end

Vegas::Runner.new(app, 'rack_app')