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.

Define the license if you are using in Build.PL. If you are using MakeMaker (Makefile.PL) you should upgrade to ExtUtils::MakeMaker version 6.31.

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: Devel::GraphVizProf, GraphViz, GraphViz::Data::Grapher, GraphViz::No, GraphViz::Parse::RecDescent, GraphViz::Parse::Yacc, GraphViz::Parse::Yapp, GraphViz::Regex, GraphViz::Small, GraphViz::XML

Split the distribution, or fix the version numbers to make them consistent (use the highest version number to avoid version downgrade).

Error: 0.01,0.02,0.8,2.02

Add all modules contained in this distribution to the META.yml field 'provides'. Module::Build or Dist::Zilla::Plugin::MetaProvides do this automatically for you.

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.