无法加载Rails Server（3.0.11，ruby 1.9.2），没有要加载的此类文件-链轮/ railtie（LoadError）

Question

Using the Hartl tutorial.

Command: rails s

Response:

/Users/davidpardy/rails_projects/sample_app/config/application.rb:8:in `require': no such file     to load -- sprockets/railtie (LoadError)
    from /Users/davidpardy/rails_projects/sample_app/config/application.rb:8:in `<top     (required)>'
    from /Users/davidpardy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.11/lib/rails    /commands.rb:28:in `require'
    from /Users/davidpardy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.11/lib/rails    /commands.rb:28:in `block in <top (required)>'
    from /Users/davidpardy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.11/lib/rails    /commands.rb:27:in `tap'
    from /Users/davidpardy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.11/lib/rails    /commands.rb:27:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

application.rb file below

require File.expand_path('../boot', __FILE__)

# Pick the frameworks you want:
require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "sprockets/railtie"
#require "rails/test_unit/railtie"

if defined?(Bundler)
  # If you precompile assets before deploying to production, use this line
  Bundler.require(*Rails.groups(:assets => %w(development test)))
  # If you want your assets lazily compiled in production, use this line
  #Bundler.require(:default, :assets, Rails.env)
end

module SampleApp
  class Application < Rails::Application
    config.encoding = "utf-8"
    config.filter_parameters += [:password]
    config.assets.enabled = true
    config.assets.version = '1.0'
  end
end

Tried commenting out sprockets, just created more problems (and nothing came of that, unfortunately).

WUG thoughts?

Answer 1

You've downgraded your app to rails 3.0 but there are still a number of places with your application references 3.1 only methods or files.

sprockets/railtie is one of those, there will also be settings in your environment.rb referring to the asset pipeline and probably some others too (the wrap params stuff springs to mind). You would need at the very least to remove all of those.

As someone new to rails I'd strongly suggest you start with the version of rails the tutorial you are following was written for and stick with it.