Rails 5.1.6 无法启动：main:Object 的未定义局部变量或方法“config”答案

【问题标题】：Rails 5.1.6 can't start: undefined local variable or method `config' for main:ObjectRails 5.1.6 无法启动：main:Object 的未定义局部变量或方法“config”
【发布时间】：2019-02-03 14:47:36
【问题描述】：

我刚醒来，无法使用 rails s 启动 rails 服务器。我收到以下错误：

$ rails s
c:/Sites/wtna/config/application.rb:9:in `<top (required)>': undefined local variable or method `config' for main:Object (NameError)
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/commands/server/server_command.rb:133:in `require'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/commands/server/server_command.rb:133:in `block in perform'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/commands/server/server_command.rb:130:in `tap'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/commands/server/server_command.rb:130:in `perform'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/command/base.rb:63:in `perform'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/command.rb:44:in `invoke'
    from C:/RailsInstaller/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-5.1.6/lib/rails/commands.rb:16:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

10 小时前一切正常。有什么建议吗？

【问题讨论】：

您也可以从application.rb 文件中发布您的代码吗？可能是 config 变量正试图在它定义的范围之外被访问。
您在过去 10 小时内是否进行了更改？其他人是否更改了某些内容，而您使用 git/svn 更新将其删除？
谢谢，伙计们。我昨天在 application.rb 中添加了一行，一旦被注释掉，我就会再次运行（见下文）。

标签： ruby-on-rails

【解决方案1】：

事实证明，在 config/application.rb（我从 dotdotdotPaul:How can I completely disable CoffeeScript in a Rails 3.1 app? 获取）中注释掉以下行可以解决问题：

config.generators.javascript_engine :js

【讨论】：