yum install gcc-c++ patch readline readline-devel zlib zlib-devel
yum install libyaml-devel libffi-devel openssl-devel make
yum install bzip2 autoconf automake libtool bison iconv-devel
rvm 安装要用普通用户.
然后切换taobao 源头.
[sun]~>rvm gemset create
[sun]~>rvm use 2.2.2
Gemset ‘‘ does not exist, ‘rvm ruby-2.2.2 do rvm gemset create ‘ first, or append ‘--create‘.
[sun]~>rvm --create ruby-2.2.2
http://www.jianshu.com/p/70d674bffd12
http://stackoverflow.com/questions/15848635/rvm-not-recognizing-gemset
