Gentoo's Bugzilla –
Attachment 353458 Details for
Bug 477074sys-apps/portage-2.1.12.13 emerging net-firewall/iptables-1.4.19.1 - /usr/lib64/portage/bin/eapi.sh: line 99: `___eapi_best_version_and_has_version_support_--host-root': not a valid identifier