Rails控制台错误：undefined method `each' for nil:NilClass (NoMethodError)

Question

Rails控制台错误：undefined method `each' for nil:NilClass (NoMethodError)

6

任何尝试在我的Rails应用程序的根目录中运行rails console都会产生以下错误：

未定义方法“each”以供nil:NilClass使用（NoMethodError）

完整的堆栈跟踪：

 /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/railtie.rb:245:in `each_registered_block': undefined method `each' for nil:NilClass (NoMethodError)
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/railtie.rb:224:in `run_console_blocks'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/application.rb:461:in `block in run_console_blocks'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/engine/railties.rb:13:in `each'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/engine/railties.rb:13:in `each'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/application.rb:461:in `run_console_blocks'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/engine.rb:442:in `load_console'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands/console.rb:34:in `initialize'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands/console_helper.rb:9:in `new'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands/console_helper.rb:9:in `start'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands/commands_tasks.rb:78:in `console'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/command.rb:20:in `run'
  from /Users/gnerkus/.rvm/gems/ruby-2.2.3@rails-experiments/gems/railties-5.0.0.beta1.1/lib/rails/commands.rb:19:in `<top (required)>'
  from bin/rails:4:in `require'
  from bin/rails:4:in `<main>'

我已经追踪到错误来源于 Rails lib 中 railtie.rb 文件中的这个块：

def each_registered_block(type, &block)
  klass = self.class
  while klass.respond_to?(type)
    # The ':console' type doesn't seem to exist
    klass.public_send(type).each(&block) 
    klass = klass.superclass
  end
end

这句话的意思是“它（指代的对象）来源于以下这个代码块：

def run_console_blocks(app) #:nodoc:
  each_registered_block(:console) { |block| block.call(app) }
end

我卸载了spring gem并安装了rubocop gem。否则，我的Gemfile包含默认gems。

我的Ruby版本是2.2.3，高于Rails 5推荐的2.2.2版本。

Ruby版本：2.2.3p173 Rails版本：5.0.0.beta1.1 RVM版本：1.26.11

- gnerkus

请您能否发布完整的堆栈跟踪？ - Nick Aschenbach

3个回答

0

gem install spring 对我有用。

我的问题是：

/usr/local/bin/NMONMerge.rb:209:in `block in <main>': undefined method `each' for nil:NilClass (NoMethodError)
from /usr/local/bin/NMONMerge.rb:191:in `each'
from /usr/local/bin/NMONMerge.rb:191:in `<main>'

- Thomas

-2

你需要安装 Spring Gem

gem install spring  --pre

- vipin

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- gnerkus · Accepted Answer

错误是由于 web-console gem 引起的，可以在这里找到相关信息：运行 rails console 时出错。当报告此错误时，web-console 版本为 3.1.0。执行 rails console 时，web-console 的版本为 3.0.0，似乎没有产生任何错误。

您需要确保您的 web-console 版本为 3.1.1 或更高版本，因为该问题已在 3.1.1 版本中修复。