ubuntu 11.10 系统，刚才更新 rvm 碰到这个问题：

rvm get stable % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 185 100 185 0 0 107 0 0:00:01 0:00:01 --:--:-- 1057 100 8798 100 8798 0 0 2582 0 0:00:03 0:00:03 --:--:-- 8102 BASH 3.2.48 required (you have 4.2.10(1)-release) Could not update RVM, get some help at #rvm IRC channel at freenode servers.

怎么 rvm 开始要求 bash 版本了？而且还是低版本的 bash？这怎么整？