$ git clone -n https://src.fedoraproject.org/rpms/R-preprocessCore.git /var/lib/mock/f45-build-6363-348/root/chroot_tmpdir/scmroot/R-preprocessCore
Cloning into '/var/lib/mock/f45-build-6363-348/root/chroot_tmpdir/scmroot/R-preprocessCore'...
$ git fetch origin d8f4940a1252f66a4936d1f53311501d6565d594:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-preprocessCore
 * [new ref]         d8f4940a1252f66a4936d1f53311501d6565d594 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d8f4940 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild