We have an out of date version of harfbuzz. Add the a YAML github autogen for the latest on Funtoo next.
Upstream GitHub repo for autogen: https://github.com/harfbuzz/harfbuzz
Upstream ebuild for autogen Jinja2 template: https://gitweb.gentoo.org/repo/gentoo.git/tree/media-libs/harfbuzz/harfbuzz-4.3.0.ebuild