mongrel with gem 0.9.5

%RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require': no such file to load -- %RUBY_HOME%/lib/ruby/gems/1.8/gems/mon
grel-1.1.2-x86-mswin32-60/lib/mongrel/init.rb (MissingSourceFile)
        from %RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:495:in `require'
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:342:in `new_constants_in'
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:495:in `require'
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/gem_plugin-0.2.3/lib/gem_plugin.rb:134:in `load'
        from %RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:166:in `each'
        from %RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:166:in `each'
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/gem_plugin-0.2.3/lib/gem_plugin.rb:112:in `load'
         ... 21 levels...
        from %RUBY_HOME%/lib/ruby/gems/1.8/gems/rails-1.2.6/lib/commands/server.rb:39
        from %RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
        from %RUBY_HOME%/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
        from script/server:3

gem update --system したら、mongrelが動かなくなったっす。

This is a known problem with RubyGems 0.9.5 You should downgrade back to 0.9.4 until 0.9.5.1 or greater get released (since I think is fixed on trunk). Oh, also remove the -d (daemonize) option from the command line, daemonize requires fork() which don't work under Windows. For running mongrel_rails in a deattached (background) fashion, please take a look at mongrel_service gem.

こまった、とりあえずWEBrickでしのぐっす