I guess the pinentry depend in evolution is to ensure graphical frontend is available. The correct depend string for that would be: || ( app-crypt/pinentry[gtk] app-crypt/pinentry-qt app-crypt/pinentry[qt4] ) Thanks!
The separate pinentry-qt is newer than pinentry[qt4]
+ 30 Sep 2010; Samuli Suominen <ssuominen@gentoo.org> + evolution-2.28.3.1-r1.ebuild, evolution-2.30.3.ebuild: + Fix pinentry dependencies on latest 2.28 and 2.30 series wrt #339265. with eva's permission