我有一个简单的应用程序：
require "sinatra"
get "/" do
raise "Oops!"
end
由于这是一个调试环境，我希望看到一个＆＃34; RuntimeError：糟糕！＆＃34;显示在浏览器中。相反，似乎Sinatra崩溃了：
NoMethodError at / undefined method `join' for #<String:0x00000002b74bf0> Ruby /home/tomas/.rvm/.../gems/sinatra-1.4.5/lib/sinatra/show_exceptions.rb: in rescue in call, line 37 Web GET 127.0.0.1/
在控制台中进行Backtrace：
RuntimeError - Oops!:
test.rb:5:in `block in '
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1603:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1603:in `block in compile!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:966:in `[]'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:966:in `block (3 levels) in route!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:985:in `route_eval'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:966:in `block (2 levels) in route!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1006:in `block in process_route'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1004:in `catch'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1004:in `process_route'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:964:in `block in route!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:963:in `each'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:963:in `route!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1076:in `block in dispatch!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `block in invoke'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `catch'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `invoke'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1073:in `dispatch!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:898:in `block in call!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `block in invoke'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `catch'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1058:in `invoke'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:898:in `call!'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:886:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/xss_header.rb:18:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/path_traversal.rb:16:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/json_csrf.rb:18:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/base.rb:49:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/base.rb:49:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-protection-1.5.3/lib/rack/protection/frame_options.rb:31:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/logger.rb:15:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/commonlogger.rb:33:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:217:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:210:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/head.rb:13:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/methodoverride.rb:22:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/show_exceptions.rb:21:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:180:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:2014:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1478:in `block in call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1788:in `synchronize'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1478:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/handler/webrick.rb:89:in `service'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
[2014-10-08 12:42:42] ERROR NoMethodError: undefined method `join' for #<String:0x007f52e055ce38>
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/show_exceptions.rb:37:in `rescue in call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/show_exceptions.rb:21:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:180:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:2014:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1478:in `block in call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1788:in `synchronize'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/sinatra-1.4.5/lib/sinatra/base.rb:1478:in `call'
/home/tomas/.rvm/gems/ruby-2.0.0-p481@test/gems/rack-1.6.0.beta/lib/rack/handler/webrick.rb:89:in `service'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/home/tomas/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
localhost - - [08/Oct/2014:12:42:42 CEST] "GET / HTTP/1.1" 500 340
这对我完全没有帮助。这里发生了什么？
答案 0 :(得分：11)
看起来recent change in Rack在Sinatra中引入了这个错误，has been fixed但修复程序没有（在撰写本文时）已包含在发行版中。
最简单的修复（直到更新的Sinatra gem发布）将使用早期版本的Rack（此更改目前仅在1.6.0.beta中）。如果您正在使用Bundler，或者在脚本开头附近（Gemfile之前的任何地方），如果您不使用此行，请将此行添加到require：
gem 'rack', '1.5.2'