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: Dancer::Plugin::Database::Core::Handle

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

Error: 0.16,0.20

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.

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