$ git clone -n https://src.fedoraproject.org/rpms/grace.git /var/lib/mock/f45-build-12966-444/root/chroot_tmpdir/scmroot/grace
Cloning into '/var/lib/mock/f45-build-12966-444/root/chroot_tmpdir/scmroot/grace'...
$ git fetch origin 3bcbc85dbd82da9ba370a9aa661de433982c8ff0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grace
 * [new ref]         3bcbc85dbd82da9ba370a9aa661de433982c8ff0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3bcbc85 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild