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
