Due to legal/naming issues, the upstream project was discontinued and removed from CPAN (replaced by a placeholder announcement). The project was replaced by Monitoring::Plugin. See the perl-monitoring-plugin AUR package. On Sun, Jan 3, 2021 at 6:01 PM <notify@aur.archlinux.org> wrote:

micwoj92 [1] filed an orphan request for perl-nagios-plugin [2]:

Marked out of date 3 months, no response from maintainer.

[1] https://aur.archlinux.org/account/micwoj92/ [2] https://aur.archlinux.org/pkgbase/perl-nagios-plugin/