scrubyt出现RubyInline (= 3.6.3)错误

在irb中输入

require 'scrubyt'

出现以下错误信息:

Gem::Exception: can't activate RubyInline (= 3.6.3), already activated RubyInline-3.6.6]
        from /usr/lib/ruby/1.8/rubygems.rb:254:in `activate'
        from /usr/lib/ruby/1.8/rubygems.rb:272:in `activate'
        from /usr/lib/ruby/1.8/rubygems.rb:271:in `each'
        from /usr/lib/ruby/1.8/rubygems.rb:271:in `activate'
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from (irb):3
irb(main):004:0> exit

解决方法：
输入以下命令：

gem uninstall RubyInline

出现：

Select gem to uninstall:
 1. RubyInline-3.6.3
 2. RubyInline-3.6.6
 3. All versions

选择2，回车，这样就删除了3.6.6版本了

不知为什么？当使用

gem install scrubyt

安装scrubyt时，总是会把RubyInline的两个版本都安装下去