窝里个去，不使用sudo吧rvm requirements执行不成功。加上sudo吧rvm requirements调用的brew install又不行。好吧，就按上面说的将brew转换到root模式。

ls -al /usr/local/bin/brew

-rwxr-xr-x  1 twer  admin  703 Mar 14  2013 /usr/local/bin/brew

$ sudo chown root:admin /usr/local/bin/brew

Password:

$ ls -al /usr/local/bin/brew

-rwxr-xr-x  1 root  admin  703 Mar 14  2013 /usr/local/bin/brew

OK。再执行吧。

$ sudo rvm requirements

Password:

Checking requirements for osx.

Certificates in '/usr/local/etc/openssl/cert.pem' already are up to date.

Requirements installation successful.

搞定。把brew再切换到原来的用户和组。

$ sudo chown twer:admin /usr/local/bin/brew