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 '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: SPVM::BlessedObject, SPVM::BlessedObject::Array, SPVM::BlessedObject::Class, SPVM::BlessedObject::String, SPVM::Bool, SPVM::Byte, SPVM::ByteList, SPVM::Cloner, SPVM::Comparator::Byte, SPVM::Comparator::Double, SPVM::Comparator::Float, SPVM::Comparator::Int, SPVM::Comparator::Long, SPVM::Comparator::Object, SPVM::Comparator::Short, SPVM::Comparator::String, SPVM::Complex_2d, SPVM::Complex_2f, SPVM::Document::Benchmark, SPVM::Document::ExchangeAPI, SPVM::Document::LanguageSpecification, SPVM::Document::Modules, SPVM::Document::NativeAPI, SPVM::Document::Tutorial, SPVM::Double, SPVM::DoubleList, SPVM::EqualityChecker, SPVM::EqualityChecker::SameObject, SPVM::Float, SPVM::FloatList, SPVM::Fn, SPVM::Hash, SPVM::Hash::Entry, SPVM::Int, SPVM::IntList, SPVM::List, SPVM::Long, SPVM::LongList, SPVM::Regex, SPVM::Regex::Pattern, SPVM::Regex::Replacer, SPVM::Short, SPVM::ShortList, SPVM::StringBuffer, SPVM::StringList, SPVM::Stringer, SPVM::Time, SPVM::Time::Info, SPVM::Unicode

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.