$ git clone -n https://src.fedoraproject.org/rpms/R-FMStable.git /var/lib/mock/f40-build-789268-135696/root/chroot_tmpdir/scmroot/R-FMStable
Cloning into '/var/lib/mock/f40-build-789268-135696/root/chroot_tmpdir/scmroot/R-FMStable'...
$ git fetch origin 3409810c6fd3f5e48e87f1c5646385d24ec66cd0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-FMStable
 * [new ref]         3409810c6fd3f5e48e87f1c5646385d24ec66cd0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3409810 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild