When we added support for LibreSSL in Gentoo, we decided to introduce USE=libressl as an implementation-discriminating flag, similar to USE=libav and USE=graphicsmagick, where USE=libav only discriminates between libav and ffmpeg, not in optionally enabling support for it. That is, USE=ffmpeg and USE=libav have orthogonal ends, and work together to make Gentoo more pleasant to use for users. The alternative would have been to require REQUIRED_USE constructs, which while more correct from a specification point-of-view, has led to users polluting their package.use files with (often transient) configs, making the Gentoo experience less pleasant. As such, USE=libressl should generally not appear in REQUIRED_USE, as this defeats its purpose: seamlessly switching from openssl to libressl by changing a single global flag. Having a single globally valid and well-defined meaning for USE=libressl is essential to this end.
All completed. closing as DONE
