$ git clone -n https://src.fedoraproject.org/rpms/R-digest.git /var/lib/mock/f45-build-6045-346/root/chroot_tmpdir/scmroot/R-digest
Cloning into '/var/lib/mock/f45-build-6045-346/root/chroot_tmpdir/scmroot/R-digest'...
$ git fetch origin 928579f2f3a1fc15fac62e605f57992297acd1c9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-digest
 * [new ref]         928579f2f3a1fc15fac62e605f57992297acd1c9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 928579f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild