Version 1.2.1 is available upstream. Please consider updating! It seems that version 1.2.1 is available upstream, while the latest version in the Gentoo tree is 1.2.0-r1. You think this warning is false? Read more about it here.
Snappy is a compression/decompression library.
It does not aim for maximum compression, or compatibility with any
other compression library; instead, it aims for very high speeds and
reasonable compression.