$ git clone -n https://src.fedoraproject.org/forks/nfrayer/rpms/grub2.git /var/lib/mock/f43-build-58899197-6569108/root/chroot_tmpdir/scmroot/grub2
Cloning into '/var/lib/mock/f43-build-58899197-6569108/root/chroot_tmpdir/scmroot/grub2'...
$ git fetch origin 5c361bf70675268ba79cc904eaa601e3b3470a99:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/nfrayer/rpms/grub2
 * [new ref]         5c361bf70675268ba79cc904eaa601e3b3470a99 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5c361bf ppc/mkimage: SBAT support on powerpc