uninitialized constant> ActionCable :: Server :: Configuration :: ApplicationCable
当我运行服务器时，它的抛出错误显示在下面的日志中。 我google了很多但没有理由支持它。 有人请说清楚。
的Gemfile
source 'https://rubygems.org' # Bundle edge Rails instead: gem 'rails', github: 'rails/rails' gem 'rails', '>= 5.0.0.beta1', ' 0.10.0.rc1' group :development, :test do gem 'byebug' end gem 'puma' group :development do gem 'spring' end 日志：
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/configuration.rb:15:in `initialize': uninitialized constant ActionCable::Server::Configuration::ApplicationCable (NameError) from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `new' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `block in ' from /home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:72:in `block in mattr_reader' from /home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:55:in `each' from /home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:55:in `mattr_reader' from /home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:208:in `mattr_accessor' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:12:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:7:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:6:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable.rb:43:in `server' from /home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/process/logging.rb:10:in `' from /home/pd/Documents/EventsApp/config.ru:7:in `block in ' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:55:in `instance_eval' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:55:in `initialize' from /home/pd/Documents/EventsApp/config.ru:in `new' from /home/pd/Documents/EventsApp/config.ru:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:49:in `eval' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:49:in `new_from_string' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:40:in `parse_file' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:318:in `build_app_and_options_from_config' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:218:in `app' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:56:in `app' from /home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:353:in `wrapped_app' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:134:in `log_to_stdout' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:74:in `start' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:90:in `block in server' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:85:in `tap' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:85:in `server' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:49:in `run_command!' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/command.rb:20:in `run' from /home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands.rb:19:in `' from /home/pd/Documents/EventsApp/bin/rails:9:in `require' from /home/pd/Documents/EventsApp/bin/rails:9:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/rails.rb:28:in `load' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/rails.rb:28:in `call' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/command.rb:7:in `call' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client.rb:28:in `run' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/bin/spring:51:in `' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/binstub.rb:11:in `load' from /home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/binstub.rb:11:in `' from /home/pd/Documents/EventsApp/bin/spring:13:in `require' from /home/pd/Documents/EventsApp/bin/spring:13:in `' from bin/rails:3:in `load' from bin/rails:3:in `'
该错误与项目中没有正确的ActionCable文件有关。 您需要app/channels/application_cable/channel.rb ，如下所示
module ApplicationCable class Channel < ActionCable::Channel::Base end end
和app/channels/application_cable/connection.rb
module ApplicationCable class Connection < ActionCable::Connection::Base end end
尝试在Rails 4.2.5中使用ActionCable时遇到了同样的问题，解决方法是将以下内容添加到config / application.rb：
config.autoload_paths += %W(#{config.root}/app/channels)
这是使用ActionCable gem：
gem 'actioncable', github: 'rails/actioncable', branch: 'archive'
根据DHH昨天的video教程 ， Spring和ActionCable依赖关系之间存在一个问题，因此在Rails 5的最终版本发布之前，您需要使用--skip-spring选项重新创建项目。
如果从先前版本升级（当actioncable不在捆绑包中时），请检查config/application.rb包含
require "action_cable/engine"