RepoMan scours the neighborhood... KEYWORDS.dropped 1 www-client/firefox/firefox-17.0.9.ebuild: hppa repo.eapi.deprecated 3 www-client/firefox/firefox-10.0.11.ebuild: 3 www-client/firefox/firefox-17.0.9.ebuild: 3 www-client/firefox/firefox-24.3.0.ebuild: 3 grep KEYWORDS firefox-17.0.9.ebuild KEYWORDS="~alpha amd64 arm -hppa ~ia64 ppc ppc64 x86 ~amd64-linux ~x86-linux" "Dropped" is not the same as -hppa.
repoman support has been removed per bug 835013. Please file a new bug (or, I suppose, reopen this one) if you feel this check is still applicable to pkgcheck and doesn't already exist.