Created attachment 453428 [details, diff] qt5ct-0.27.ebuild.diff "dbus" USE flag dependency on gtgui is needed only for tray icon and can be hidden under "trayicon" USE flag. Attached diff for the ebuild which works for me.
PR: https://github.com/gentoo/gentoo/pull/2855
Fixed in 0.27-r1: commit 02f6df9acbf526316885f5325a93ceeb0d3ad85d Author: Ilya Tumaykin <itumaykin@gmail.com> AuthorDate: Thu Nov 17 06:43:43 2016 +0300 Commit: Michael Palimaka <kensington@gentoo.org> CommitDate: Thu Nov 17 22:51:30 2016 +1100 x11-misc/qt5ct: make system tray support optional Gentoo-Bug: https://bugs.gentoo.org/599950 Closes: https://github.com/gentoo/gentoo/pull/2855 Package-Manager: portage-2.3.2