循环依赖错误

Question

所以我的Gemfile目前看起来像

source 'https://rubygems.org' 

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails' 
gem 'rails', '4.2.4' 
# Use sqlite3 as the database for Active Record 
gem 'sqlite3' 
# Use SCSS for stylesheets 
gem 'sass-rails', '~> 5.0' 
# Use Uglifier as compressor for JavaScript assets 
gem 'uglifier', '>= 1.3.0' 
# Use CoffeeScript for .coffee assets and views 
gem 'coffee-rails', '~> 4.1.0' 
# See https://github.com/rails/execjs#readme for more supported runtimes 
# gem 'therubyracer', platforms: :ruby 

# Use jquery as the JavaScript library 
gem 'jquery-rails' 
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks 
gem 'turbolinks' 
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder 
gem 'jbuilder', '~> 2.0' 
# bundle exec rake doc:rails generates the API under doc/api. 
gem 'sdoc', '~> 0.4.0', group: :doc 

gem 'mathjax-rails', '~> 2.5', '>= 2.5.1' 
gem 'bootstrap-sass', '~> 3.3', '>= 3.3.5.1' 

# Use ActiveModel has_secure_password 
# gem 'bcrypt', '~> 3.1.7' 

# Use Unicorn as the app server 
# gem 'unicorn' 

# Use Capistrano for deployment 
# gem 'capistrano-rails', group: :development 

group :development, :test do 
    # Call 'byebug' anywhere in the code to stop execution and get a debugger console 
    gem 'byebug' 
end 

group :development do 
    # Access an IRB console on exception pages or by using <%= console %> in views 
    gem 'web-console', '~> 2.0' 

    # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring 
    gem 'spring' 
end 

它工作正常。有趣的是，当我删除mathjax-rails，并尝试在生产模式下运行时，我得到

/usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_dispatch/routing/url_for.rb:99:in `append_features': cyclic include detected (ArgumentError) 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_dispatch/routing/url_for.rb:99:in `include' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_dispatch/routing/url_for.rb:99:in `block in <module:UrlFor>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/concern.rb:120:in `class_eval' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/concern.rb:120:in `append_features' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionview-4.2.4/lib/action_view/railtie.rb:41:in `include' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionview-4.2.4/lib/action_view/railtie.rb:41:in `block (2 levels) in <class:Railtie>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/lazy_load_hooks.rb:45:in `block in run_load_hooks' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/lazy_load_hooks.rb:44:in `each' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/lazy_load_hooks.rb:44:in `run_load_hooks' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_controller/base.rb:266:in `<class:Base>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_controller/base.rb:164:in `<module:ActionController>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/actionpack-4.2.4/lib/action_controller/base.rb:5:in `<top (required)>' 
    from /root/StudySome/app/controllers/application_controller.rb:1:in `<top (required)>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:274:in `require' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:274:in `block in require' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:240:in `load_dependency' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:274:in `require' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:360:in `require_or_load' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:317:in `depend_on' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.2.4/lib/active_support/dependencies.rb:233:in `require_dependency' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:472:in `block (2 levels) in eager_load!' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:471:in `each' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:471:in `block in eager_load!' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:469:in `each' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:469:in `eager_load!' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/engine.rb:346:in `eager_load!' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/application/finisher.rb:56:in `each' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/application/finisher.rb:56:in `block in <module:Finisher>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `instance_exec' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `run' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/initializable.rb:55:in `block in run_initializers' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:226:in `block in tsort_each' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:429:in `each_strongly_connected_component_from' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:347:in `block in each_strongly_connected_component' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:345:in `each' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:345:in `call' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:345:in `each_strongly_connected_component' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:224:in `tsort_each' 
    from /usr/local/rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/tsort.rb:203:in `tsort_each' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/initializable.rb:54:in `run_initializers' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/application.rb:352:in `initialize!' 
    from /root/StudySome/config/environment.rb:5:in `<top (required)>' 
    from /root/StudySome/config.ru:3:in `require' 
    from /root/StudySome/config.ru:3:in `block in <main>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/builder.rb:55:in `instance_eval' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/builder.rb:55:in `initialize' 
    from /root/StudySome/config.ru:in `new' 
    from /root/StudySome/config.ru:in `<main>' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/builder.rb:49:in `eval' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/builder.rb:49:in `new_from_string' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/builder.rb:40:in `parse_file' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:299:in `build_app_and_options_from_config' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:208:in `app' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/server.rb:61:in `app' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:336:in `wrapped_app' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:272:in `start' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/server.rb:80:in `start' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:80:in `block in server' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `tap' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `server' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:39:in `run_command!' 
    from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands.rb:17:in `<top (required)>' 
    from bin/rails:4:in `require' 
    from bin/rails:4:in `<main>' 
=> Booting WEBrick 
=> Rails 4.2.4 application starting in production on http://159.203.240.211:80 
=> Run `rails server -h` for more startup options 
=> Ctrl-C to shutdown server 
Exiting 

为什么？我只是想从MathJax CDN中加载MathJax ...

Answer 1

即使您删除了该宝石，您的代码中仍可能有一些mathjax引用。在宝石的usage instructions中，您似乎需要将一些代码添加到routes.rb以及app/views/layouts/application.html.erb。如果那些参考文献在那里，删除他们应该修复这个组织。