Ruby threads cannot be used in RubyCocoa without patches to the Ruby interpreter

Question

I found this error in Ruby console while I am testing a Rails application.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib /mongrel.rb:285:  
in `run': Ruby threads cannot be used in RubyCocoa without patches to the Ruby interpreter

So I guess I have to patch or re-install RubyCocoa. But I don't found any content to do this. or you may have the better way to solve this?

This is my environment:

• ruby 1.8.7
• Rails 2.3.3
• Mac OSX 10.6

Answer 1

As Matthew points out in his answer, it may be a plug-in that is causing this. He found that attachment_fu is one cause. (It can use Core Image for its image processing.) Creating a file in config/initializers (for a Rails application) with this line will silence the warning, at the expense of requiring one of the other image processors:

Technoweenie::AttachmentFu.default_processors.delete('CoreImage')

This isn't a problem for me; I deploy to non-Mac servers, and since those can't use CoreImage, I want to run the same thing during development anyway.

If you look at /System/Library/Frameworks/RubyCocoa.framework/Versions/A/Resources/ruby/osx/ objc/ruby_addition.rb, this is at the bottom of the file:

class Thread
  class << self
    alias :pre_rubycocoa_new :new

    # Override Thread.new to prevent threads being created if there isn't 
    # runtime support for it
    def new(*args,&block)
      unless defined? @_rubycocoa_threads_allowed then
        # If user has explicilty disabled thread support, also disable the 
        # check (for debugging/testing only)
        @_rubycocoa_threads_allowed = ENV['RUBYCOCOA_THREAD_HOOK_DISABLE'] || 
          OSX::RBRuntime.isRubyThreadingSupported?
      end
      if !@_rubycocoa_threads_allowed then
        warn "#{caller[0]}: Ruby threads cannot be used in RubyCocoa without patches to the Ruby interpreter"
      end
      pre_rubycocoa_new(*args,&block)
    end
  end
end

So for starters, we get a warning, but then it proceeds to call the original Thread.new anyway. I don't believe this warning is a real problem. It's just annoying to see it constantly in the console.

If you want to track down what's pulling in the monkey patch to Thread, grep for something that pulls in osx/cocoa:

$ irb
>> Thread.new { puts 'hi' }
hi=> #<Thread:0x1011328e0 run>
>> require 'osx/cocoa'

=> true
>> Thread.new { puts 'hi' }
(irb):3:in `irb_binding': Ruby threads cannot be used in RubyCocoa without patches to the Ruby interpreter
hi=> #<Thread:0x103bf76e8 run>

Answer 2

It is probably not mongrel that is pulling it in but some plugin in your rails application. For me attachment_fu was the culprit

Answer 3

Quick hack:

$ RUBYCOCOA_THREAD_HOOK_DISABLE=1 ./script/server --debugger

Different quick hack:

$ echo "ENV['RUBYCOCOA_THREAD_HOOK_DISABLE']='1'" > config/initializers/disable_rubycocoa_warning.rb