rails update to 2.0

升级前，
D:\ruby>gem -v: 0.95
D:\ruby>rails -v: 1.2.3

升级命令如下：

1、D:\ruby>gem update --system
2、D:\ruby>gem update rails --include-dependencies --source http://gems.rubyonrails.org/

升级完，
D:\ruby>gem -v: 1.0.1
D:\ruby>rails -v
d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:379:in `report_activate_error': RubyG
em version error: activesupport(1.4.2 not = 2.0.2) (Gem::LoadError)
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:311:in `activate'
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:337:in `activate'
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:336:in `each'
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:336:in `activate'
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:65:in `active_gem_with_o
ptions'
        from d:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:50:in `gem'
        from d:/ruby/bin/rails:18

再执行：
D:\ruby>gem update activesupport

• rake-0.6.2.gem
• actionmailer-1.1.5.gem
• actionpack-1.11.2.gem
• actionwebservice-1.0.0.gem
• activerecord-1.13.2.gem
• activesupport-1.2.5.gem

update or install 这些插件即可。