$ git clone -n https://src.fedoraproject.org/rpms/R-deldir.git /var/lib/mock/f45-build-6060-346/root/chroot_tmpdir/scmroot/R-deldir
Cloning into '/var/lib/mock/f45-build-6060-346/root/chroot_tmpdir/scmroot/R-deldir'...
$ git fetch origin 8a0fda5cf47d9c503d4ad8cd92a7c7e25a2ac7bc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-deldir
 * [new ref]         8a0fda5cf47d9c503d4ad8cd92a7c7e25a2ac7bc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a0fda5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild