Please add ppc64 keyword for sys-apps/sandbox-2.17 in ::musl . Going forward, we can nuke this from overlay, as release 2.18 has musl fixes included - see https://gitweb.gentoo.org/proj/sandbox.git
https://gitweb.gentoo.org/proj/musl.git/commit/?id=c0afea5daa179ca6409299de9bb5c93a29e31e11