what you need to do is change the xs_init prototype from _((void)) to something like (s) without the leading _.
I came across the very same problem with my fedora9 box. Made the change, compiled, then pp still wouldn'y work. You may very need to then install module build from CPAN. Then you'll be right.
edit the pp script to disinclude use pp; (and the next line), either way @ISA will complain.
PS- by no means am I C programmer (as much as I wish I had the time to play) or competant in any way.
in reply to Building PAR::Packer on Fedora9 i386