On Mar 29, 2023, at 20:29, Jacob Bachmeyer <jcb62281@xxxxxxxxx> wrote: > > Digest::SHA was installable from CPAN long before it was a core module More to the point, it’s _still_ installable that way, and the current version’s minimum Perl requirement is 5.3.0, from 1996: https://metacpan.org/pod/Digest::SHA If you had to pin to an old version of the package to get it to install, I’d have less sympathy with this argument. > the Perl version does *not* indicate its presence It’s a good bet, though. The thing is, it *isn't* the Autoconf Way: test for features, not versions. There is one good use case for “use v5.xx” in a Perl program: when you’re requiring a particular version of the Perl interpreter, to use language features that didn’t exist and couldn’t be patched in with packages before that. This is not that case. However, I will repeat a point from an earlier thread: the generated configure scripts from the new version of Autoconf will continue running on these older systems. The only thing being broken is the ability to *generate* configure scripts with Autoconf on those ancient systems.