$ git clone -n https://src.fedoraproject.org/rpms/grubby.git /var/lib/mock/f42-build-862876-171198/root/chroot_tmpdir/scmroot/grubby
Cloning into '/var/lib/mock/f42-build-862876-171198/root/chroot_tmpdir/scmroot/grubby'...
$ git fetch origin a94c545ae243d8050eec603e6df38c84e2f5f5ca:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grubby
 * [new ref]         a94c545ae243d8050eec603e6df38c84e2f5f5ca -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a94c545 Add riscv64 support