Rails 5.1.4无法启动并给我错误：JRuby或Windows Exiting不支持工作模式

Question

我尝试启动我的rails服务器，但下面收到错误消息，我该如何解决呢

C:\Sites\sample_app>rails s
=> Booting Puma
=> Rails 5.1.4 application starting in development
=> Run `rails server -h` for more startup options
  Please add the following to your Gemfile to avoid polling for changes:
    gem 'wdm', '>= 0.1.0' if Gem.win_platform?
  Please add the following to your Gemfile to avoid polling for changes:
    gem 'wdm', '>= 0.1.0' if Gem.win_platform?
ERROR: worker mode not supported on JRuby or Windows
Exiting

Answer 1

根据Puma的this问题页面，可以通过在puma.rb中注释掉以下行来解决：

workers Integer(ENV['WEB_CONCURRENCY'] || 2)