http://www.perlmonks.org?node_id=1017004


in reply to CPAN won't work on Mountain Lion following attempt to install Bundle::CPAN

Another thing: Don't use sudo when installing modules after installing perlbrew. A sudo install post perlbrew will give directories created by the install only root privileges, which will adversely affect subsequent attempts to install modules without sudo, and the whole point of perlbrew is not to have to use sudo.

If you did use sudo, read this link on how I got the permissions corrected.