If you are using Build.PL define the {requires}{perl} = VERSION field. If you are using MakeMaker (Makefile.PL) you should upgrade ExtUtils::MakeMaker to 6.48 and use MIN_PERL_VERSION parameter. Perl::MinimumVersion can help you determine which version of Perl your module needs.

Add a META.json to the distribution. Your buildtool should be able to autogenerate it.

Fix the problematic entry.

Error: ^* matches null string many times in regex; marked by <-- HERE in m/(?:^(.*/)?CVS/.*)|(?:^Makefile(.old)?$)|(?:^Build$)|(?:^Clean$)|(?:^RollingBuild$)|(?:^blib/.*)|(?:^pm_to_blib$)|(?:^.cvsignore$)|(?:^MANIFEST.bak$)|(?:^testcheck$)|(?:^.*/\.cvsignore$)|(?:^lib/Class/MethodMaker/(?:array|hash|scalar)\.pm$)|(?:^lib/Class/MethodMaker/\.\#.*$)|(?:^lib/Class/MethodMaker\.(?:bs|o|c)$)|(?:^html(?:/.*)?$)|(?:^(.*/)?.cvsignore$)|(?:^INFO.yaml$)|(?:^_build/)|(?:^misc/)|(?:^* <-- HERE ~$)|(?:^make-dist$)|(?:^MethodMaker\.(?:bs|o|c)$)/ at lib/ExtUtils/Manifest.pm line 440.

Add 'use warnings' (or its equivalents) to all modules, or convince us that your favorite module is well-known enough and people can easily see the modules warn when something bad happens.

Error: Class::MethodMaker

Add a 'repository' resource to the META.yml via 'meta_add' accessor (for Module::Build) or META_ADD parameter (for ExtUtils::MakeMaker).

This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.