Man pages matching name message::passing::output::stdout in section 3pm:

Message::Passing::Output::STDOUT.3pm.en	debian 10 / libmessage-passing-perl
Message::Passing::Output::STDOUT.3pm.en	debian 11 / libmessage-passing-perl
Message::Passing::Output::STDOUT.3pm.en	debian 12 / libmessage-passing-perl