Haml installation in Rails app failing - ruby-on-rails

Question

I have a small rails app I got all gung-ho on tonight wanting to convert all the erb to haml templates. The Haml docs suggest running haml --rails /path/to/app to install it as a plugin (using the gem already installed on the system).
Unfortunately, when I attempt to start the webserver for rails, I receive the following error:
/code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:443:in `load_missing_constant': uninitialized constant Haml (NameError)
from /code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:80:in `const_missing'
from /code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:92:in `const_missing'
from /code/src/myapp/config/environment.rb:15
from ./script/../config/../vendor/rails/railties/lib/initializer.rb:111:in `run'
from /code/src/myapp/config/environment.rb:5
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `require'
from /code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:156:in `require'
from /code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:521:in `new_constants_in'
from /code/src/myapp/vendor/rails/activesupport/lib/active_support/dependencies.rb:156:in `require'
from /code/src/myapp/vendor/rails/railties/lib/commands/server.rb:84
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in `require'
from ./script/server:3
It's barfing on a line in my environment file:
# Be sure to restart your server when you modify this file
RAILS_GEM_VERSION = '2.3.2' unless defined? RAILS_GEM_VERSION
require File.join(File.dirname(__FILE__), 'boot')
Rails::Initializer.run do |config|
# Add additional load paths for your own custom dirs
config.load_paths += %W(
#{RAILS_ROOT}/lib/
)
# Specify gems that this application depends on and have them installed with rake gems:install
config.gem 'twitter'
config.gem 'newrelic_rpm'
Haml::Template.options[:format] = :html5
Haml::Template.options[:attr_wrapper] = '"'
config.plugins = [ :all ]
config.active_record.observers = :user_observer
config.time_zone = 'UTC' # "rake -D time" for all time zone names.
end
ConsumerConfig = YAML.load(File.read(Rails.root + 'config' + 'twitter-auth.yml'))
The error is on the line attempting to set some Haml options (Haml::Template.options[:format] = :html5). Installing the haml plugin with script/plugin install yields the same error, as does require haml at the top of environment.rb. Not sure if it makes a difference, but rails is frozen in vendor/rails.
This is very confusing to me, please assist if you can figure this out.

Answer 1

Does it work if you move the Haml::Template configuration after the Initializer block? It could be that Rails isn't loading the plugin until after the initializer is run.