当我有管理员模型时，Sidekiq 无法启动答案

【问题标题】：Sidekiq fails to start when have I have admin model当我有管理员模型时，Sidekiq 无法启动
【发布时间】：2014-08-27 12:12:44
【问题描述】：

我正在使用 sidekiq 处理后台作业，这不是我第一次使用 sidekiq。

问题：

如果我有一个名为 admin 的设计模型，Sidekiq 将无法启动。

class Admin < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :registerable, :timeoutable and :omniauthable
  devise :database_authenticatable, :recoverable, :rememberable, :trackable, :validatable
end

如果我评论这个“管理员”模型类，那么 sidekiq 将按预期正常启动。目前我使用的是 sidekiq 默认配置。

错误回溯：

bundle exec sidekiq
Admin is not a class
/home/ninja/workspace/howismyschool/app/models/admin.rb:1:in `<top (required)>'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:443:in `load'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:443:in `block in load_file'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:633:in `new_constants_in'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:442:in `load_file'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:342:in `require_or_load'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:307:in `depend_on'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:225:in `require_dependency'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:468:in `block (2 levels) in eager_load!'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:467:in `each'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:467:in `block in eager_load!'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:465:in `each'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:465:in `eager_load!'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/engine.rb:346:in `eager_load!'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/application/finisher.rb:58:in `each'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/application/finisher.rb:58:in `block in <module:Finisher>'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/initializable.rb:30:in `instance_exec'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/initializable.rb:30:in `run'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/initializable.rb:55:in `block in run_initializers'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:226:in `block in tsort_each'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:427:in `each_strongly_connected_component_from'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:347:in `block in each_strongly_connected_component'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `each'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `call'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:345:in `each_strongly_connected_component'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:224:in `tsort_each'
/home/ninja/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/tsort.rb:205:in `tsort_each'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/initializable.rb:54:in `run_initializers'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/railties-4.1.4/lib/rails/application.rb:300:in `initialize!'
/home/ninja/workspace/howismyschool/config/environment.rb:5:in `<top (required)>'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `require'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `block in require'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:232:in `load_dependency'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `require'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/sidekiq-3.2.0/lib/sidekiq/cli.rb:230:in `boot_system'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/sidekiq-3.2.0/lib/sidekiq/cli.rb:49:in `run'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/gems/sidekiq-3.2.0/bin/sidekiq:8:in `<top (required)>'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/bin/sidekiq:23:in `load'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/bin/sidekiq:23:in `<main>'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/bin/ruby_executable_hooks:15:in `eval'
/home/ninja/.rvm/gems/ruby-2.1.2@howismyschoolisdoing/bin/ruby_executable_hooks:15:in `<main>'

应用环境：

红宝石 2.1.2
导轨 4.1.4
Ubuntu 14.04

【问题讨论】：

标签： ruby ruby-on-rails-4 devise backgroundworker sidekiq

【解决方案1】：

该错误与 sidekiq 无关。 is not a class 异常很可能是由命名冲突引起的（您在某处定义了常量 Admin）。检查您的项目是否有 Admin 常量并重命名它。

如何在控制台（irb）中重现错误：

1.9.3-p448 :001 > A = 1
 => 1
1.9.3-p448 :002 > class A
1.9.3-p448 :003?> end
TypeError: A is not a class

【讨论】：

是的，这可能是个问题。我在我的应用程序中安装了 activeadmin，这似乎是原因。当我从应用程序中完全评论 activeadmin 时，sidekiq 正常启动。我正在查看 activeadmin gem 以查找此 Admin 常量的定义位置，但找不到。所以问题在于这个管理员名称冲突，但在哪里找不到。现在我要重命名我的管理类。