Install this version:
emerge -a =dev-perl/JSON-XS-VersionOneAndTwo-0.310.0
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =dev-perl/JSON-XS-VersionOneAndTwo-0.310.0
Or alternatively:
emerge --autounmask-write -a =dev-perl/JSON-XS-VersionOneAndTwo-0.310.0
# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
DIST_AUTHOR=LBROCARD
DIST_VERSION=0.31
inherit perl-module
DESCRIPTION="Support versions 1 and 2 of JSON::XS"
SLOT="0"
KEYWORDS="~amd64 ~x86"
RDEPEND="dev-perl/JSON-XS"
BDEPEND="${RDEPEND}
test? (
dev-perl/Test-Pod
)
"