Created attachment 441306 [details] app-editors:focuswriter-1.5.6:20160721-073220.log With dev-qt/qtconcurrent installed I don't see this.
Thanks, fixed in git. It appears to be required at build time only. https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=0132b725f7c323000bff4ae72624c9e17909259f