$ git clone -n https://src.fedoraproject.org/rpms/R-unix.git /var/lib/mock/f40-build-2175656-51067/root/chroot_tmpdir/scmroot/R-unix
Cloning into '/var/lib/mock/f40-build-2175656-51067/root/chroot_tmpdir/scmroot/R-unix'...
$ git fetch origin 5e47219620f544151ee0c2166297e850620ac7c9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-unix
 * [new ref]         5e47219620f544151ee0c2166297e850620ac7c9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5e47219 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild