Install this version:
emerge -a =app-emacs/smartparens-9999
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =app-emacs/smartparens-9999
Or alternatively:
emerge --autounmask-write -a =app-emacs/smartparens-9999
# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
NEED_EMACS=22
inherit elisp git-r3
DESCRIPTION="Automatic insertion, wrapping and paredit-like navigation w/ user defined pairs."
HOMEPAGE="https://github.com/Fuco1/smartparens"
EGIT_REPO_URI="https://github.com/Fuco1/smartparens.git"
KEYWORDS="~amd64 ~x86"
LICENSE="GPL-3"
SLOT="0"
RDEPEND=">=app-emacs/dash-2.13.0"
SITEFILE="50${PN}-gentoo.el"
src_prepare() {
rm ${PN}-pkg.el
default
}