$ git clone -n https://src.fedoraproject.org/rpms/mfem.git /var/lib/mock/f40-build-2600545-63129/root/chroot_tmpdir/scmroot/mfem
Cloning into '/var/lib/mock/f40-build-2600545-63129/root/chroot_tmpdir/scmroot/mfem'...
$ git fetch origin 049fc0d195d8629a90ac8e61877fde586c9371b4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mfem
 * [new ref]         049fc0d195d8629a90ac8e61877fde586c9371b4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 049fc0d Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild