Believe it or not, but I benchmarked this ... and there is a slight advantage to not recompiling strings via eval. Depending on how hungry you are for CPU cycles...

foreach my $p (@prereqs)
{
  (my $x = $p) =~ s[::][/]g;
  $x .= '.pm';
  eval {
    require $x;
  }
  if ($@) {
    print "Missing prerequisite - $p\n";
    exit 0;
  }
}
[download]

A bit more code - but a bit faster, too. The tradeoff is up to you.