The system Perl on OSX will be updated/reverted by Apple whenever they want.

While developping WWW::Mechanize::Chrome and getting it to install on OSX, I found that using a Perl provided/compiled by homebrew worked "best" in the sense that the libraries and packages provided by homebrew work together with the Perl provided by homebrew and CPAN.

In my case, Imager::PNG would not compile+install with the system Perl, but does so flawlessly with homebrew.