gem install rails でエラーが出たよ

[root@localhost ~]# gem install --test rails
Successfully installed rake-0.8.7
Successfully installed activesupport-2.3.5
Successfully installed activerecord-2.3.5
Successfully installed rack-1.0.1
Successfully installed actionpack-2.3.5
Successfully installed actionmailer-2.3.5
Successfully installed activeresource-2.3.5
Successfully installed rails-2.3.5
8 gems installed
Installing ri documentation for rake-0.8.7...
Installing ri documentation for activesupport-2.3.5...
Installing ri documentation for activerecord-2.3.5...
Installing ri documentation for rack-1.0.1...
Installing ri documentation for actionpack-2.3.5...
Installing ri documentation for actionmailer-2.3.5...
Installing ri documentation for activeresource-2.3.5...
Installing RDoc documentation for rake-0.8.7...
Installing RDoc documentation for activesupport-2.3.5...
Installing RDoc documentation for activerecord-2.3.5...
Installing RDoc documentation for rack-1.0.1...
Installing RDoc documentation for actionpack-2.3.5...
Installing RDoc documentation for actionmailer-2.3.5...
Installing RDoc documentation for activeresource-2.3.5...
:0:Warning: Gem::SourceIndex#search support for String patterns is deprecated
There are no unit tests to run for rake-0.8.7
:0:Warning: Gem::SourceIndex#search support for String patterns is deprecated
There are no unit tests to run for activesupport-2.3.5
:0:Warning: Gem::SourceIndex#search support for String patterns is deprecated
There are no unit tests to run for activerecord-2.3.5
:0:Warning: Gem::SourceIndex#search support for String patterns is deprecated
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- test/s             pec (LoadError)
        from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from ./test/spec_rack_auth_basic.rb:1
        from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/validator.rb:181:in `unit_test'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/validator.rb:181:in `each'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/validator.rb:181:in `unit_test'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/commands/install_command.rb:135:in `execute'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/commands/install_command.rb:133:in `each'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/commands/install_command.rb:133:in `execute'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/command.rb:136:in `invoke'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:105:in `process_args'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:75:in `run'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/gem_runner.rb:39:in `run'
        from /usr/bin/gem:24

なんだろ。

とりあえず一旦全部 gem uninstall して、もう一回同じことをやったら、今度は問題なく入った。
謎。。