無法在Rails 5中啓動rails服務器

Question

我使用RVM安裝Rails。一切工作正常，像生成一個新的應用程序rails new app。 bundle install和其他每個命令都可以正常運行。 但是當我用rails -server啓動我的Rails服務器時，出現以下錯誤，我無法理解。

rails aborted! 
NameError: undefined local variable or method `rver' for #<Rake::Application:0x00563aa7540988> 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.2/lib/rails/commands/rake_proxy.rb:12:in `block in run_rake_task' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.2/lib/rails/commands/rake_proxy.rb:11:in `run_rake_task' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.2/lib/rails/commands/commands_tasks.rb:51:in `run_command!' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/railties-5.0.2/lib/rails/commands.rb:18:in `<top (required)>' 
/home/mrrobot/rails/demo/app/bin/rails:9:in `require' 
/home/mrrobot/rails/demo/app/bin/rails:9:in `<top (required)>' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/client/rails.rb:28:in `load' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/client/rails.rb:28:in `call' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/client/command.rb:7:in `call' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/client.rb:30:in `run' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/bin/spring:49:in `<top (required)>' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/binstub.rb:31:in `load' 
/home/mrrobot/.rvm/gems/ruby-2.4.0@global/gems/spring-2.0.1/lib/spring/binstub.rb:31:in `<top (required)>' 
/home/mrrobot/rails/demo/app/bin/spring:15:in `require' 
/home/mrrobot/rails/demo/app/bin/spring:15:in `<top (required)>' 
bin/rails:3:in `load' 
bin/rails:3:in `<main>' 
(See full trace by running task with --trace) 

紅寶石版本：2.4.0p0（2016年12月24日修訂版57164）[x86_64的Linux的]

的Rails版本：5.0.2

RubyGems的版本：2.6 .11

Answer 1

這是rails server，沒有破折號

或者只是

rails s