including module works in development, fails at startup in production?

I've authored a module that lives in my lib folder. I'm including it at startup by putting it in my environment.rb file as follows

# Load the rails application
require File.expand_path('../application', __FILE__)

# Initialize the rails application
MyProject::Application.initialize!

ActiveRecord::Base.send :include, MyProject::Has::Formatter
include MyProject::EventFormatters

This works great in development but if I try to run in production mode or if I deploy my app to production I get the following stack trace when the server tries to start up:

=> Booting WEBrick
=> Rails 3.0.3 application starting in production on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.3/lib/active_record/base.rb:1008:in `method_missing': undefined local variable or method `has_formatter' for #<Class:0x808f830> (NameError)
        from C:/Data/myproject/app/models/event.rb:2
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:227:in `load_dependency'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:346:in `require_or_load'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:300:in `depend_on'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:216:in `require_dependency'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/engine.rb:138:in `eager_load!'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/engine.rb:137:in `each'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/engine.rb:137:in `eager_load!'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/engine.rb:135:in `each'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/engine.rb:135:in `eager_load!'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/application.rb:108:in `eager_load!'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/application/finisher.rb:41
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `instance_exec'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `run'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/initializable.rb:50:in `run_initializers'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `each'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `run_initializers'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/application.rb:134:in `initialize!'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/application.rb:77:in `send'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
        from C:/Data/myproject/config/environment.rb:5
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
        from C:/Data/myproject/config.ru:3
        from C:/Ruby187/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/builder.rb:46:in `instance_eval'
        from C:/Ruby187/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/builder.rb:46:in `initialize'
        from C:/Data/myproject/config.ru:1:in `new'
        from C:/Data/myproject/config.ru:1

Now here is the most mind boggling part of the whole thing: If I set config开发者_如何学C.cache_classes = false in config/environments/production.rb then I don't get that stack trace and the app behaves the same in production mode as it does dev mode!!

What about settings config.cache_classes = false makes including a module in this fashion work in production? Am I including the module in a wrong/weird way?

Hope I'm totally, right, I'll at least present my point of view:

In development, all your classes are lazy loaded. This way, you can easily change them since they're loaded only when necessary. This means that:

MyProject::Application.initialize!

does not load module content which requires:

ActiveRecord::Base.send :include, MyProject::Has::Formatter
include MyProject::EventFormatters

which is included afterwards, it makes the whole thing working.

In production, modules and classes are really loaded => crash, they need their dependencies!

As a result, put:

ActiveRecord::Base.send :include, MyProject::Has::Formatter
include MyProject::EventFormatters

in an initializer you create in config/initializers, call it active_record_extension.rb for instance.

Does autoloading not work for your scenario?

# config/application.rb
config.autoload_paths += %W(#{config.root}/lib)

# lib/my_project/event_formatters.rb
module MyProject
  module EventFormatters
    # .. etc. ...
  end
end