Install this version:
emerge -a =app-emacs/xr-2.2# Copyright 1999-2026 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
NEED_EMACS="27.1"
ELPA_CONTAINER_KIND=tar
inherit elpa
DESCRIPTION="Convert string regexp to rx notation"
# No releases, no tags
# SRC_URI="
# !test? ( ${SRC_URI} )
# test? ( https://github.com/mattiase/xr/archive/refs/tags/${PV}.tar.gz -> ${P}.tar.gz )"
KEYWORDS="amd64 ~x86"
SLOT="0"