At the end of make DESTDIR=/tank/root installkernel: ... kldxref: error while reading /tank/root/boot/kernel/wsp.ko: Bad address kldxref: error while reading /tank/root/boot/kernel/xhci.ko: Bad address kldxref: error while reading /tank/root/boot/kernel/zfs.ko: Bad address kldxref: error while reading /tank/root/boot/kernel/zlib.ko: Bad address
Fixed in https://svnweb.freebsd.org/changeset/base/293852