Could the media-libs/libraw-0.17.x series to be keyworded already? It seems to work fine with all parties. Also, the libraw-0.17.0_beta3 is out.
Bumped in git to 0.17.0, thanks for the report! https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=aecf6d7b9e3e19fe9796ac6840d2b326445ff5b8