"${EPREFIX}"/usr/bin/moc is not the right location for moc in Qt >=4.8.6 This should be changed to "$(qt4_get_bindir)"/moc from qmake-utils.eclass
Thanks, +*pinentry-0.9.0-r3 (22 Mar 2015) + + 22 Mar 2015; Kristian Fiskerstrand <k_f@gentoo.org> +pinentry-0.9.0-r3.ebuild: + Use qt4_get_bindir from qmake-utils instead of hardcoding moc path. Fixes + #544110 +