DEPEND="${RDEPEND}" Virtuals don't build so they don't need any build-time dependencies. The line should be removed.
commit 92790fe40dea9e079de1ed5ae2738d86a23b7314 Author: Justin Lecher <jlec@gentoo.org> Date: Fri Apr 14 12:23:13 2017 +0100 virtual/fortran: Drop unnecessary build dependency Bump to EAPI 6 Gentoo-Bug: https://bugs.gentoo.org/show_bug.cgi?id=614120 Package-Manager: Portage-2.3.5, Repoman-2.3.2 Signed-off-by: Justin Lecher <jlec@gentoo.org> https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=92790fe40dea9e079de1ed5ae2738d86a23b7314