PAR and Module::Scandeps vs autobox

PAR is a handy tool for dealing with your Perl application's many dependencies.
You can quickly bundle up the app + all requirements, and then run it on other machines. It's great when you don't feel like building half of CPAN just to run a temporary utility somewhere.

It generally works fairly well, but it relies upon Module::ScanDeps to report what those dependencies are.

And unfortunately I've been totally stumped by it when the autobox module is involved.. but only on the Debian Etch (4.0 and 4.5) platform; it works fine on Ubuntu 8.10 and 9.04.

To demonstrate, take the following mini script:

#!/usr/bin/perl
use strict;
use warnings;
use autobox;

print "Hello world!"->length;

sub SCALAR::length {
    return length(shift);
}

Now run this to build a .par file from it:
pp -p -o test.par test.pl

Now we know that the test script used autobox.. So this test.par should contain autobox.pm and autobox.so, right?

$ unzip -l test.par|grep autobox
$

Wrong. Where did it go?
Attempting to run the resulting par on another etch system does, predictably, fail due to a missing autobox module.

Running the same commands on Ubuntu 9.04 work just fine. Both systems are running the latest version of PAR, PAR::Packer, and Module::ScanDeps.