Install this version:
emerge -a =app-vim/dirdiff-1.1.5# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
inherit vim-plugin
DESCRIPTION="vim plugin: diff and merge two directories recursively"
HOMEPAGE="https://www.vim.org/scripts/script.php?script_id=102"
LICENSE="BSD"
KEYWORDS="amd64 x86"
RDEPEND="sys-apps/diffutils"
VIM_PLUGIN_HELPFILES="${PN}.txt"