$ git clone -n https://src.fedoraproject.org/rpms/R-filehash.git /var/lib/mock/f45-build-6061-346/root/chroot_tmpdir/scmroot/R-filehash
Cloning into '/var/lib/mock/f45-build-6061-346/root/chroot_tmpdir/scmroot/R-filehash'...
$ git fetch origin 5a5af716ea1676be5f89317de5314c8f5b7d9332:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-filehash
 * [new ref]         5a5af716ea1676be5f89317de5314c8f5b7d9332 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5a5af71 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild