我是铁轨上的红宝石初学者。当我尝试gem list时，它会显示以下信息：
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/rack-protection-1.1.2.gemspec]: invalid date format in specification: "2011-10-01 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/whenever-0.7.0.gemspec]: invalid date format in specification: "2011-09-02 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/chronic-0.6.4.gemspec]: invalid date format in specification: "2011-09-09 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/uuid-2.3.4.gemspec]: invalid date format in specification: "2011-09-02 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/tilt-1.3.3.gemspec]: invalid date format in specification: "2011-08-25 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/sinatra-1.3.0.gemspec]: invalid date format in specification: "2011-10-01 00:00:00.000000000Z"
Invalid gemspec in [/usr/lib/ruby/gems/1.8/specifications/rack-cache-1.0.3.gemspec]: invalid date format in specification: "2011-08-27 00:00:00.000000000Z"
当我尝试运行脚本/服务器或rake -T时，它仍会显示相同的消息。