Man pages matching name devel::assertc99 in section 3pm:

Devel::AssertC99.3pm.en	debian 10 / libdevel-checkcompiler-perl
Devel::AssertC99.3pm.en	debian 11 / libdevel-checkcompiler-perl
Devel::AssertC99.3pm.en	debian 12 / libdevel-checkcompiler-perl