Rails - Mar 2011 - "no such file to load -- dispatcher (LoadError)" on starting mongrel process

After I updated to Rails 3.0, I encountered the following error on
booting mongrel process.
Can anyone advise? Thank you.

** Starting Mongrel listening at 0.0.0.0:3000
** Starting Rails with development environment...
/Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/
dependencies.rb:239:in `require'': no such file to load -- dispatcher
(LoadError)
	from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/
active_support/dependencies.rb:239:in `require''
	from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/
active_support/dependencies.rb:225:in `load_dependency''
	from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/
active_support/dependencies.rb:596:in `new_constants_in''
	from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/
active_support/dependencies.rb:225:in `load_dependency''
	from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/
active_support/dependencies.rb:239:in `require''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/rails.rb:148:in
`rails''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:113:in `cloaker_''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:
149:in `call''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:
149:in `listener''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:99:in `cloaker_''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:
50:in `call''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:
50:in `initialize''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:84:in `new''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:84:in `run''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/command.rb:212:in
`run''
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:281
	from /usr/bin/mongrel_rails:19:in `load''
	from /usr/bin/mongrel_rails:19

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Hej Ryo,

have you added mongrel to your gems?
If not simply add "gem mongrel" to your Gemfile.
"rails server" will then automatically use mongrel.

Best,
Sebastian

--------------------------
Sebastian Gräßl
sebastian-30c1IgTnpsdP52+qxqhqIQ@public.gmane.org
http://validcode.me 

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Hi Sebastian,

Thank you very much for your advice.
Your advice worked well!

Thanks,
Ryo

On Mar 21, 4:54 am, Sebastian Gräßl
<sebast...-30c1IgTnpsdP52+qxqhqIQ@public.gmane.org>
wrote:
> Hej Ryo,
>
> have you added mongrel to your gems?
> If not simply add "gem mongrel" to your Gemfile.
> "rails server" will then automatically use mongrel.
>
> Best,
> Sebastian
>
> --------------------------
> Sebastian Gräßl
> sebast...-30c1IgTnpsfwk2tF5GeW7Q@public.gmane.org://validcode.me
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