The list of core perl modules changes; vendors add/remove their own modules, and sometimes installvendorlib is same as installsitelib ( http://p3rl.org/INSTALL#Installation-Directories )

The only safe move is to get a list of all installed modules and their versions, which is called an bundle ... links on autobundles and things like that see Re^3: Is there an easier way to find and install modules on Linux? (metacpan autocompletion)