Workaround for error I get with toughtbot's mile_marker

Full trace

NoMethodError in WelcomeController#index

You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.include?
RAILS_ROOT: /Users/ryan/source/idp2/git/protosite

Application Trace | Framework Trace | Full Trace
vendor/plugins/mile_marker/lib/mile_marker.rb:37:in `enabled?'
vendor/plugins/mile_marker/lib/mile_marker.rb:9:in `initialize_mile_marker'
vendor/plugins/mile_marker/lib/mile_marker.rb:14:in `add_initialize_mile_marker'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/callbacks.rb:178:in `send'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/callbacks.rb:178:in `evaluate_method'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/callbacks.rb:166:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/filters.rb:662:in `run_after_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/filters.rb:619:in `call_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/filters.rb:610:in `perform_action_without_benchmark'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/rescue.rb:136:in `perform_action_without_caching'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/caching/sql_cache.rb:13:in `perform_action'
/Library/Ruby/Gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
/Library/Ruby/Gems/1.8/gems/activerecord-2.2.2/lib/active_record/query_cache.rb:8:in `cache'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/caching/sql_cache.rb:12:in `perform_action'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/base.rb:524:in `send'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/base.rb:524:in `process_without_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/filters.rb:606:in `process_without_session_management_support'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/session_management.rb:134:in `sass_old_process'
/Library/Ruby/Gems/1.8/gems/haml-2.0.4/lib/sass/plugin/rails.rb:19:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/base.rb:392:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:183:in `handle_request'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:110:in `dispatch_unlocked'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:123:in `dispatch'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:122:in `synchronize'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:122:in `dispatch'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:132:in `dispatch_cgi'
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:39:in `dispatch'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/rails.rb:76:in `process'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/rails.rb:74:in `synchronize'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/rails.rb:74:in `process'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in `process_client'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `each'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `process_client'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `initialize'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `new'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `initialize'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `new'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:282:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:281:in `each'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:281:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:128:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/command.rb:212:in `run'
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:281
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:142:in `load_without_new_constant_marking'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:142:in `load'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:521:in `new_constants_in'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:142:in `load'
/Library/Ruby/Gems/1.8/gems/rails-2.2.2/lib/commands/servers/mongrel.rb:64
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `require'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:153:in `require'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:521:in `new_constants_in'
/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:153:in `require'
/Library/Ruby/Gems/1.8/gems/rails-2.2.2/lib/commands/server.rb:49
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `require'
script/server:3
Request

Parameters:

None
Show session dump

Response

Headers:

{"Status"=>"200 OK",
 "cookie"=>[],
 "Content-Type"=>"text/html",
 "Cache-Control"=>"no-cache"}

rails_integration_test.rb

# Note: this doesn't fail when the patch is not applied, 
# but I'm not sure of any other way to try to encapsulate
# this in a test or why it's not throwing in testing
require File.expand_path(File.join(
  File.dirname(__FILE__), *%w".. .. .. .. config environment.rb"))
require File.expand_path(File.join(File.dirname(__FILE__), 'test_helper'))

require 'action_controller'
require 'action_controller/test_process'

class RailsIntegrationTest < Test::Unit::TestCase
  class ::SampleController < ::ActionController::Base
    include Thoughtbot::MileMarkerHelper
    after_filter :add_initialize_mile_marker
    
    def dummy_render
      render(:nothing => true)
    end
  end
  
  def setup
    @controller = SampleController.new
    @request = ActionController::TestRequest.new
    @response = ActionController::TestResponse.new
  end
  
  def test_add_initialize_mile_marker_does_not_throw
    assert_nothing_thrown do
      get :dummy_render
    end
  end
end

self.enabled_actioncontroller_scope.patch

diff --git a/vendor/plugins/mile_marker/lib/mile_marker.rb b/vendor/plugins/mile_marker/lib/mile_marker.rb
index d69483c..95832bf 100644
--- a/vendor/plugins/mile_marker/lib/mile_marker.rb
+++ b/vendor/plugins/mile_marker/lib/mile_marker.rb
@@ -34,7 +34,7 @@ module Thoughtbot
 
     # Return true if the Mile Marker functionality is enabled for the current environment
     def self.enabled?
-      environments.include?(ENV['RAILS_ENV'])
+      @@environments.include?(ENV['RAILS_ENV'])
     end
     
     def self.enable