#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

package my;
use Carp;

sub test{ croak 'UNIMPLEMENTED '.( caller(0) )[3]; }

package main;

for my $num (0..9)
{
  open(my $fh, '>', 'my.pm');
  print $fh <<EOC;
package my;

sub test{ $num }

1;
EOC
  close($fh);

  if(require 'my.pm')
  {
    print my::test()."\n";
    delete($INC{'my.pm'});
  }
}