There is an ongoing outage on the primary CPAN mirror. It is possible to work around the issue by using MetaCPAN as a mirror.

SYNOPSIS

my $manager = Archer::Parallel::ForkManager->new;
$manager->run(
    {
        num => 30,
        callback => sub {
            my $elem = shift;
            $self->run_hook('process', {elem => $elem});
        }
    }
);