mac中brew link Error

Error: Cowardly refusing to 'sudo brew link'
You can use brew with sudo, but only if the brew executable is owned by root.
However, this is both not recommended and completely unsupported so do so at
your own risk.

ll /usr/local/bin | grep brew
-rwxr-xr-x  1 chenxiaoyu  admin   656B Mar 11  2016 brew

将brew用户改为root：
sudo chown root:admin /usr/local/bin/brew
然后运行sudo brew link xxx，解决。