故障现象：
[root@cloudmaster gem]# gem install rails -lERROR: Error installing rails: activemodel requires builder (~> 3.0.0, runtime)[root@cloudmaster gem]#
故障分析：
gem包使用本地安装，而本地builder-3.1.4.gem版本大于3.0.0，按提示应该不是此问题；尝试其他方法解决都行不通，故找来另一台机器直接gem install rails一下，，之后gem list结果如下：
[root@ezCloud ~]# gem install railsSuccessfully installed rails-3.2.91 gem installedInstalling ri documentation for rails-3.2.9…Installing RDoc documentation for rails-3.2.9…[root@ezCloud ~]# gem list
*** LOCAL GEMS ***
actionmailer (3.2.9)actionpack (3.2.9)activemodel (3.2.9)activerecord (3.2.9)activeresource (3.2.9)activesupport (3.2.9)arel (3.0.2)builder (3.0.4)bundler (1.2.3)daemons (1.1.9)erubis (2.7.0)eventmachine (1.0.0)headers (0.0.1)hike (1.2.1)i18n (0.6.1)journey (1.0.4)json (1.7.5, 1.4.6)libraries (0.1.6)mail (2.4.4)mime-types (1.19)multi_json (1.5.0)nokogiri (1.5.6)polyglot (0.3.3)rack (1.4.1)rack-cache (1.2)rack-protection (1.3.2)rack-ssl (1.3.2)rack-test (0.6.2)rails (3.2.9)railties (3.2.9)rake (10.0.3)rdoc (3.12)sequel (3.42.0)sinatra (1.3.3)sinatra-sequel (0.9.0)sprockets (2.2.2)thin (1.5.0)thor (0.16.0)tilt (1.3.3)treetop (1.4.12)tzinfo (0.3.35)[root@ezCloud ~]#
人爱美，不仅需要服饰居室之美，还需要心灵品德之美。
