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: App::picadata, PICA::Data, PICA::Data::Field, PICA::Error, PICA::Parser::Base, PICA::Parser::Binary, PICA::Parser::Import, PICA::Parser::JSON, PICA::Parser::PIXML, PICA::Parser::PPXML, PICA::Parser::Patch, PICA::Parser::Plain, PICA::Parser::Plus, PICA::Parser::XML, PICA::Patch, PICA::Path, PICA::Schema, PICA::Schema::Builder, PICA::Writer::Base, PICA::Writer::Binary, PICA::Writer::Generic, PICA::Writer::Import, PICA::Writer::JSON, PICA::Writer::PIXML, PICA::Writer::PPXML, PICA::Writer::Patch, PICA::Writer::Plain, PICA::Writer::Plus, PICA::Writer::XML