Install this version:
emerge -a =app-admin/sudoers-emerge-1.0-r1
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =app-admin/sudoers-emerge-1.0-r1
Or alternatively:
emerge --autounmask-write -a =app-admin/sudoers-emerge-1.0-r1
EAPI=8
DESCRIPTION="Installs a sudoers.d drop-in to enable emerge without password"
HOMEPAGE="https://www.sudo.ws/"
LICENSE="public-domain"
SLOT="0"
KEYWORDS="~amd64 ~arm ~arm64"
S="${WORKDIR}"
src_install() {
insinto /etc/sudoers.d
newins "${FILESDIR}"/10-emerge 10-emerge
fperms 0440 /etc/sudoers.d/10-emerge
}