Man pages matching name devel::dwarn in section 3pm:

Devel::Dwarn.3pm.en	debian 10 / libdata-dumper-concise-perl
Devel::Dwarn.3pm.en	debian 11 / libdata-dumper-concise-perl
Devel::Dwarn.3pm.en	debian 12 / libdata-dumper-concise-perl