Created attachment 489284 [details] build log Clear interface mismatch.
This is fixed in the latest upstream version fcitx-libpinyin-0.5.1.
I sent a PR pinning libpinyin dependency to version 1.3.0-r1 in fcitx-libpinyin-0.3.3 ebuild in order to work around it for the time being. https://github.com/gentoo/gentoo/pull/5484
app-i18n/fcitx-libpinyin-0.5.1 is now in the tree. https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=d2c7c6eddfda15f34c511ae1407ae2225105fe43
Oops, the bug title I set. Anyway, thanks all!