Sign the dist as the last step before creating the archive. Take care not to modify/regenerate dist meta files or the manifest.

Error: Old SIGNATURE detected. Please inform the module author to regenerate SIGNATURE using Module::Signature version 0.82 or newer. gpg: Signature made Thu 18 Dec 2014 07:09:55 AM JST gpg: using DSA key 31F9562596406EA0 gpg: Can't check signature: No public key ==> BAD/TAMPERED signature detected! <==

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

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.