第一次使用 rails 5，tsort_each 出现问题答案

【问题标题】：First time using rails 5, trouble with tsort_each第一次使用 rails 5，tsort_each 出现问题
【发布时间】：2016-02-08 21:51:35
【问题描述】：

这是我第一次使用 Rails 5。我正在尝试运行； rails s，它给了我这个：

$ rails s
=> Booting Puma
=> Rails 5.0.0.beta2 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
DEPRECATION WARNING: before_filter is deprecated and will be removed in Rails 5.1. Use before_action instead. (called from block in tsort_each at /Users/ericcarpentier/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/tsort.rb:226)
DEPRECATION WARNING: after_filter is deprecated and will be removed in Rails 5.1. Use after_action instead. (called from block in tsort_each at /Users/ericcarpentier/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/tsort.rb:226)
DEPRECATION WARNING: alias_method_chain is deprecated. Please, use Module#prepend instead. From module, you can access the original method using super. (called from block in tsort_each at /Users/ericcarpentier/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/tsort.rb:226)
DEPRECATION WARNING: alias_method_chain is deprecated. Please, use Module#prepend instead. From module, you can access the original method using super. (called from block in tsort_each at /Users/ericcarpentier/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/tsort.rb:226)
Exiting
/Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/activesupport-5.0.0.beta2/lib/active_support/logger_silence.rb:23:in `level': undefined method `[]' for nil:NilClass (NoMethodError)
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/server.rb:140:in `log_to_stdout'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/server.rb:76:in `start'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/commands_tasks.rb:90:in `block in server'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/commands_tasks.rb:85:in `tap'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/commands_tasks.rb:85:in `server'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/command.rb:20:in /`run'
  from /Users/ericcarpentier/.rvm/gems/ruby-2.2.2/gems/railties-5.0.0.beta2/lib/rails/commands.rb:19:in `<top (required)>'
  from bin/rails:9:in `require'
  from bin/rails:9:in `<main>'

【问题讨论】：

您的任何控制器或助手中是否有 before_filter 或 after_filter？
不，我没有为任何控制器或助手使用 before_filter 或 after_filter。
我注释掉了 .rvm/gems/ruby-2.2.2/gems/activesupport-5.0.0.beta2/lib/active_support/logger_silence.rb 中的 'level' 方法，它暂时解决了问题，但想找到一个永久的解决方案。
以下...我遇到了同样的问题。 @RickRoberts 解决方法已将其备份并运行，但在此问题解决之前我不想部署。
我创建了一个 github 问题，但其中一位 rails 核心成员说这是由于第 3 方 gem rails_12 因素造成的。 github.com/rails/rails/issues/23566

标签： ruby-on-rails ruby-on-rails-5

【解决方案1】：

在我的 Gemfile 中，我有：

gem 'rails_12factor'

我遇到了同样的错误

我把 Gemfile 改成这样：

group :production, :staging do
    gem 'rails_12factor'
end

捆绑安装，它现在可以工作了。试试看

【讨论】：