无法在cygwin上运行fastri:未初始化的常量gem::version(nameerror)

我正在尝试在Windows中的cygwin上运行的emacs上设置fastri(http://eigenclass.org/hiki/fastri)。Ruby的安装也来自Cygwin,而不是Ruby的Windows版本。 下载、解包tarball并运行setup.rb后,当我尝试运行qri或fri时,会收到以下错误消息:

    [/cygdrive/g]$qri
/usr/lib/ruby/1.8/rdoc/ri/ri_paths.rb:63: uninitialized constant Gem::Version (NameError)
    from /usr/lib/ruby/1.8/rdoc/ri/ri_paths.rb:59:in `each'
    from /usr/lib/ruby/1.8/rdoc/ri/ri_paths.rb:59
    from /usr/lib/ruby/site_ruby/1.8/fastri/util.rb:38:in `require'
    from /usr/lib/ruby/site_ruby/1.8/fastri/util.rb:38
    from /usr/bin/qri:6:in `require'
    from /usr/bin/qri:6

我的Ruby版本和gem环境:

[/cygdrive/g]$ruby --version
ruby 1.8.7 (2008-08-11 patchlevel 72) [i386-cygwin]
[/cygdrive/g]$gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.4
  - RUBY VERSION: 1.8.7 (2008-08-11 patchlevel 72) [i386-cygwin]
  - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/bin/ruby.exe
  - EXECUTABLE DIRECTORY: /usr/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-cygwin
  - GEM PATHS:
     - /usr/lib/ruby/gems/1.8
     - /home/rrajagop/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://gems.rubyforge.org/

我看了一眼ri_Paths.rb,想知道gem::version应该如何包含在文件中,但我没想到。我试着把两者都加进去 require 'gem/version' 和 require 'version' 但没有快乐。我得到 'require': no such file to load -- version (LoadError)