环境：windowsXP + ruby 1.86 + rails 2.2.2
要实现全文搜索功能！
安装ferret：gem install ferret -v=0.11.5 --platform mswin32
安装acts_as_ferret：将svn://projects.jkraemer.net/acts_as_ferret/tags/stable/acts_as_ferret里的文件导出到vendor\plugins\acts_as_ferret里。
结果无法启动Mongrel了：
[code="ruby"]
=> Booting Mongrel (use 'script/server webrick' to force WEBrick)
=> Rails 2.2.2 application starting on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
** Starting Mongrel listening at 0.0.0.0:3000
** Starting Rails with development environment...
Exiting
F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- ferret_ext (MissingSourceFile)
from F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from F:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:153:in `require'
from F:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:521:in `new_constants_in'
from F:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:153:in `require'
from F:/ruby/lib/ruby/site_ruby/1.8/ferret.rb:25
from F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from F:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:153:in `require'
... 47 levels...
from F:/ruby/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/commands/server.rb:49
from F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from F:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from script/server:3
[/code]
然后把vendor\plugins\下的acts_as_ferret整个删除就能正常启动mongrel了。
我直接用gem install acts_as_ferret来安装，然后在environment.rb 里添加require 'acts_as_ferret'后，还是无法启动mongrel.
好吧，这的确是一个十分诡异的错误，而且，似乎是win下才会有的。
原因是ferret_ext找不到，而你又确实安装了，说明这个ferret_ext.so（就是C编译完后以便ruby调用的库），不在ruby可以找到的lab路径。那么，照这个逻辑可以
把
[quote] C:\ruby\lib\ruby\gems\1.8\gems\ferret-0.11.5-x86-mswin32\ext [/quote]
下的 ferret_ext.so 文件拷贝到
如下目录
[quote]C:\ruby\lib\ruby\gems\1.8\gems\ferret-0.11.5-x86-mswin32\lib[/quote]
应该就可以用，试试