$ git clone -n https://src.fedoraproject.org/rpms/R-blob.git /var/lib/mock/f40-build-2257309-54312/root/chroot_tmpdir/scmroot/R-blob
Cloning into '/var/lib/mock/f40-build-2257309-54312/root/chroot_tmpdir/scmroot/R-blob'...
$ git fetch origin 471743eaf74a2c7164a10d9dcab845f475785efa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-blob
 * [new ref]         471743eaf74a2c7164a10d9dcab845f475785efa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 471743e Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild