Versions.pm

package Versions;
require 5.006;
our $VERSION = 0.01;

my @modules;

# flag if we're in END { }
my $in_end = 0;

sub import {
    shift;
    unshift @INC, sub {
        my($self, $file) = @_;
        return if $in_end;
        push @modules, file2mod($file);
        return;
    };
}

sub file2mod {
    local $_ = shift;
    s/\.pm$//;
    s!/!::!g;
    return $_;
}

END {
    $in_end = 1;
    for my $module (@modules) {
        my $version = $module->VERSION || "(undefined)";
        print "$module $version\n";
    }
}

1;