I believe that Pod::Usage::pod2usage refers to pod2usage.PL which is a command line script; however, I think that you meant to use Pod::Usage, a part of the core. I used Pod::Usage for this script:

#!/sw/bin/perl

use strict;
use warnings;
use Getopt::Long;
use Pod::Usage;

my $help = 0;

GetOptions('help|?' => \$help) or pod2usage(2);
pod2usage(1) if ($help);
pod2usage(-exitval => 1, -verbose => 2);

__END__ 

    sample - Using GetOpt::Long and Pod::Usage

    =head1 SYNOPSIS

    sample [options] [file ...]

     Options:
       -help            brief help message
       -man             full documentation

    =head1 OPTIONS

    =over 8

    =item B<-help>

    Print a brief help message and exits.

    =item B<-man>

    Prints the manual page and exits.

    =back

    =head1 DESCRIPTION

    B<This program> will read the given input file(s) and do something
    useful with the contents thereof.

    =cut
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