Version 6.1 is available upstream. Please consider updating! It seems that version 6.1 is available upstream, while the latest version in the Gentoo tree is 5.1. You think this warning is false? Read more about it here.
Libunibreak is an implementation of the line breaking and word breaking algorithms
as described in Unicode Standard Annex 14 and Unicode Standard Annex 29. It is
designed to be used in a generic text renderer.