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.

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: DateTime::Locale, DateTime::Locale::Base, DateTime::Locale::aa, DateTime::Locale::aa_ER_SAAHO, DateTime::Locale::af, DateTime::Locale::af_NA, DateTime::Locale::ak, DateTime::Locale::am, DateTime::Locale::ar, DateTime::Locale::ar_JO, DateTime::Locale::ar_LB, DateTime::Locale::ar_QA, DateTime::Locale::ar_SA, DateTime::Locale::ar_SY, DateTime::Locale::ar_TN, DateTime::Locale::ar_YE, DateTime::Locale::as, DateTime::Locale::az, DateTime::Locale::az_Cyrl, DateTime::Locale::be, DateTime::Locale::bg, DateTime::Locale::bn, DateTime::Locale::bo, DateTime::Locale::bs, DateTime::Locale::byn, DateTime::Locale::ca, DateTime::Locale::cch, DateTime::Locale::cop, DateTime::Locale::cs, DateTime::Locale::cy, DateTime::Locale::da, DateTime::Locale::de, DateTime::Locale::de_AT, DateTime::Locale::de_BE, DateTime::Locale::dv, DateTime::Locale::dz, DateTime::Locale::ee, DateTime::Locale::el, DateTime::Locale::en, DateTime::Locale::en_AU, DateTime::Locale::en_BE, DateTime::Locale::en_BW, DateTime::Locale::en_BZ, DateTime::Locale::en_CA, DateTime::Locale::en_GB, DateTime::Locale::en_HK, DateTime::Locale::en_IE, DateTime::Locale::en_IN, DateTime::Locale::en_MT, DateTime::Locale::en_NZ, DateTime::Locale::en_PH, DateTime::Locale::en_PK, DateTime::Locale::en_SG, DateTime::Locale::en_ZA, DateTime::Locale::en_ZW, DateTime::Locale::eo, DateTime::Locale::es, DateTime::Locale::es_AR, DateTime::Locale::es_CL, DateTime::Locale::es_CO, DateTime::Locale::es_EC, DateTime::Locale::es_ES, DateTime::Locale::es_GT, DateTime::Locale::es_HN, DateTime::Locale::es_PA, DateTime::Locale::es_PE, DateTime::Locale::es_PR, DateTime::Locale::es_US, DateTime::Locale::et, DateTime::Locale::eu, DateTime::Locale::fa, DateTime::Locale::fa_AF, DateTime::Locale::fi, DateTime::Locale::fil, DateTime::Locale::fo, DateTime::Locale::fr, DateTime::Locale::fr_BE, DateTime::Locale::fr_CA, DateTime::Locale::fr_CH, DateTime::Locale::fur, DateTime::Locale::ga, DateTime::Locale::gaa, DateTime::Locale::gez, DateTime::Locale::gl, DateTime::Locale::gu, DateTime::Locale::gv, DateTime::Locale::ha, DateTime::Locale::ha_Arab, DateTime::Locale::haw, DateTime::Locale::he, DateTime::Locale::hi, DateTime::Locale::hr, DateTime::Locale::hu, DateTime::Locale::hy, DateTime::Locale::hy_AM_REVISED, DateTime::Locale::ia, DateTime::Locale::id, DateTime::Locale::ig, DateTime::Locale::ii, DateTime::Locale::is, DateTime::Locale::it, DateTime::Locale::it_CH, DateTime::Locale::iu, DateTime::Locale::ja, DateTime::Locale::ka, DateTime::Locale::kaj, DateTime::Locale::kam, DateTime::Locale::kcg, DateTime::Locale::kfo, DateTime::Locale::kk, DateTime::Locale::kl, DateTime::Locale::km, DateTime::Locale::kn, DateTime::Locale::ko, DateTime::Locale::kok, DateTime::Locale::kpe, DateTime::Locale::ku, DateTime::Locale::kw, DateTime::Locale::ky, DateTime::Locale::ln, DateTime::Locale::lo, DateTime::Locale::lt, DateTime::Locale::lv, DateTime::Locale::mk, DateTime::Locale::ml, DateTime::Locale::mn, DateTime::Locale::mr, DateTime::Locale::ms, DateTime::Locale::ms_BN, DateTime::Locale::mt, DateTime::Locale::my, DateTime::Locale::nb, DateTime::Locale::ne, DateTime::Locale::nl, DateTime::Locale::nl_BE, DateTime::Locale::nn, DateTime::Locale::nr, DateTime::Locale::nso, DateTime::Locale::ny, DateTime::Locale::om, DateTime::Locale::or, DateTime::Locale::pa, DateTime::Locale::pa_Arab, DateTime::Locale::pl, DateTime::Locale::ps, DateTime::Locale::pt, DateTime::Locale::pt_PT, DateTime::Locale::ro, DateTime::Locale::root, DateTime::Locale::ru, DateTime::Locale::ru_UA, DateTime::Locale::rw, DateTime::Locale::sa, DateTime::Locale::se, DateTime::Locale::se_FI, DateTime::Locale::sid, DateTime::Locale::sk, DateTime::Locale::sl, DateTime::Locale::so, DateTime::Locale::sq, DateTime::Locale::sr, DateTime::Locale::sr_Cyrl_BA, DateTime::Locale::sr_Latn, DateTime::Locale::sr_Latn_ME, DateTime::Locale::sr_Latn_RS, DateTime::Locale::ss, DateTime::Locale::st, DateTime::Locale::sv, DateTime::Locale::sw, DateTime::Locale::syr, DateTime::Locale::ta, DateTime::Locale::te, DateTime::Locale::tg, DateTime::Locale::th, DateTime::Locale::ti, DateTime::Locale::ti_ER, DateTime::Locale::tig, DateTime::Locale::tn, DateTime::Locale::to, DateTime::Locale::tr, DateTime::Locale::ts, DateTime::Locale::tt, DateTime::Locale::ug, DateTime::Locale::uk, DateTime::Locale::ur, DateTime::Locale::uz, DateTime::Locale::uz_Arab, DateTime::Locale::uz_Latn, DateTime::Locale::ve, DateTime::Locale::vi, DateTime::Locale::wal, DateTime::Locale::wo, DateTime::Locale::xh, DateTime::Locale::yo, DateTime::Locale::zh, DateTime::Locale::zh_Hans_SG, DateTime::Locale::zh_Hant, DateTime::Locale::zh_Hant_HK, DateTime::Locale::zh_Hant_MO, DateTime::Locale::zu, DateTime::LocaleCatalog

Add a 'repository' resource to the META.yml via 'meta_add' accessor (for Module::Build) or META_ADD parameter (for ExtUtils::MakeMaker).