Install this version:
emerge -a =sci-biology/embassy-cbstools-1.0.0.660-r1
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =sci-biology/embassy-cbstools-1.0.0.660-r1
Or alternatively:
emerge --autounmask-write -a =sci-biology/embassy-cbstools-1.0.0.660-r1
# Copyright 1999-2022 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
EBO_DESCRIPTION="Applications from the CBS group"
inherit autotools emboss-r3
KEYWORDS="~amd64 ~x86"
S="${WORKDIR}/CBSTOOLS-1.0.0.650"
PATCHES=( "${FILESDIR}"/${PN}-1.0.0.650_fix-build-system.patch )
src_prepare() {
default
eautoreconf
}