If all you are concerned about is what modules are being used, and you're not concerned about what particular methods are being used, you can use Devel::Modlist available from CPAN.
You run the script with the -d:Modlist option and when the script ends, it displays what modules packages were loaded and their version numbers, if set. The downside is you do have to run the script; the upside is this will handle dynamic including of packages.