Rails/Actionpack：警告：已经初始化常量ICS

Question

试图启动Rails服务器并得到“警告”我不明白。任何人都知道它的意思？ warning: already initialized constant ICS

这是在上下文中：

meltemi$ rails s 
=> Booting WEBrick 
=> Rails 3.1.3 application starting in development on http://0.0.0.0:3000 
=> Call with -d to detach 
=> Ctrl-C to shutdown server 
/Users/meltemi/.rvm/gems/ruby-1.9.3-p0@summit/gems/actionpack-3.1.3/lib/action_dispatch/http/mime_type.rb:101: warning: already initialized constant ICS 
[2012-01-15 12:28:34] INFO WEBrick 1.3.1 
[2012-01-15 12:28:34] INFO ruby 1.9.3 (2011-10-30) [x86_64-darwin11.2.0] 
[2012-01-15 12:28:34] INFO WEBrick::HTTPServer#start: pid=61345 port=3000 

Answer 1

它看起来像 “ICS” MIME类型越来越声明两次。如果你能找到一次实例，其中它被宣称，也许在config/initializers/mime_types.rb可以钉在这样的一个条款，除非它：

Mime::Type.register "text/calendar", :ics unless Mime::Type.lookup_by_extension(:ics) 

，如果它不存在，这应该只注册的MIME类型。