That's a really weak gotcha: Perl 4 was deprecated 28 years ago and Perl 6 is a completely different language that's been called Raku since 2019. There are no dependencies to resolve between them. It's like worry about dependency resolution between Javascript and Java. They're not even the same platform.

True. But Raku (https://raku.org #rakulang) does have an Inline::Perl5 module, which allows you to use 99.9% of modules on CPAN (basically, only the ones using source-filters, and ones that are really, really deep into the Perl internals). So there *can* be dependencies between Perl and Raku.