A key part of my plan for Upgrading from Perl 5.8 is the ability to take a perl library installed for one version of perl, and reinstall it for a different version of perl.

To do that you have to know exactly what distributions were installed in the original library. And not just which distributions, but which versions of those distributions.

I’ve a solution for that now. It turned out to be rather harder to solve than I’d thought… Continue reading →