$ git clone -n https://src.fedoraproject.org/rpms/R-kernlab.git /var/lib/mock/f39-build-1495387-34544/root/chroot_tmpdir/scmroot/R-kernlab
Cloning into '/var/lib/mock/f39-build-1495387-34544/root/chroot_tmpdir/scmroot/R-kernlab'...
$ git fetch origin 9839d8d65843b3a27b95ad473df0f48c6031ea64:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-kernlab
 * [new ref]         9839d8d65843b3a27b95ad473df0f48c6031ea64 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9839d8d Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild