Please bump the ancient sys-fs/squashfuse-0.1_p20130530 (which does not support lz4 compression of current sys-fs/squashfs-tools and which was perhaps never officially released) to the current and officially released sys-fs/squashfuse-0.1.100 see e.g. https://github.com/vasi/squashfuse/releases An updated ebuild (with EAPI=6) is available in the mv overlay, that is: https://gitweb.gentoo.org/user/mv.git/plain/sys-fs/squashfuse/squashfuse-0.1.100.ebuild (The RESTRICT="mirror" line is there only to avoid bugging gentoo mirrors.)
Thanks, this is in git: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f95904900ddcaa355f6597a9a3889cae94be7ce3