I thing a library has been lost: usr/lib/libpci.so
Read the fine changelog. *pciutils-2.2.3-r1 (24 Jun 2006) 24 Jun 2006; Mike Frysinger <vapier@gentoo.org> files/pcimodules-pciutils-2.2.0.patch, +files/pciutils-2.2.3-build.patch, +pciutils-2.2.3-r1.ebuild: Dont install libpci.so anymore, but install a PIC libpci.a like Debian.
Explained as such.