After keywording irker 2.16 on ARM the keyboard wasn't updated in later versions. (actually 2.17 does not fetch, but 2.18 works fine). Could you please re-add it.
commit 85994a457f44609607cfc7e976ca1e39caedda7e Author: Michael Weber <xmw@gentoo.org> Date: Sat Feb 11 00:09:25 2017 +0100 net-irc/irker: re-add ~arm keyword (bug 592888). Package-Manager: Portage-2.3.3, Repoman-2.3.1 net-irc/irker/irker-2.18.ebuild