Unbust build
Unbust build

Was crashing due to https://cpan.metacpan.org/authors/id/U/UG/UGEXE/Perl6/v0.1.30.tar.gz
not having a dist name present in the filename.

Fix by warning about and skipping such dists.

perl6/modules.perl6.org,perl6/modules.perl6.org,perl6/modules.perl6.org,perl6/modules.perl6.org