$ git clone -n https://src.fedoraproject.org/rpms/R-debugme.git /var/lib/mock/f45-build-6057-346/root/chroot_tmpdir/scmroot/R-debugme
Cloning into '/var/lib/mock/f45-build-6057-346/root/chroot_tmpdir/scmroot/R-debugme'...
$ git fetch origin b42b33337b3723f508c39125b2ff19213d55a9d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-debugme
 * [new ref]         b42b33337b3723f508c39125b2ff19213d55a9d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b42b333 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild