$ git clone -n https://src.fedoraproject.org/rpms/R-IRkernel.git /var/lib/mock/f40-build-2323373-58710/root/chroot_tmpdir/scmroot/R-IRkernel
Cloning into '/var/lib/mock/f40-build-2323373-58710/root/chroot_tmpdir/scmroot/R-IRkernel'...
$ git fetch origin 04d49d091cc34a1a3e51b7ea126d78877558a39c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-IRkernel
 * [new ref]         04d49d091cc34a1a3e51b7ea126d78877558a39c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 04d49d0 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild