From http://kojipkgs.fedoraproject.org/packages/perl-PAR-Packer/0.991/3.fc12/data/logs/x86_64/build.log : gcc static.o -s -Wl,-E [...] Looks like the build strips binaries before rpmbuild has had a chance to do it.
The build process uses a built binary program (myldr/static) to create the parl and parldyn binaries before installing. I cannot find any way to fix this; let it be until a perl-PAR expert appears. (I set debug_package to %{nil) to prevent creating an empty debuginfo package.)