$ git clone -n https://src.fedoraproject.org/rpms/xbyak.git /var/lib/mock/f42-build-3406855-45143/root/chroot_tmpdir/scmroot/xbyak
Cloning into '/var/lib/mock/f42-build-3406855-45143/root/chroot_tmpdir/scmroot/xbyak'...
$ git fetch origin 517e78743af1f21609efbd4312a639a3307cca00:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xbyak
 * [new ref]         517e78743af1f21609efbd4312a639a3307cca00 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 517e787 Update to 7.24.1