$ git clone -n https://src.fedoraproject.org/rpms/module-build.git /var/lib/mock/f40-build-2613694-64086/root/chroot_tmpdir/scmroot/module-build
Cloning into '/var/lib/mock/f40-build-2613694-64086/root/chroot_tmpdir/scmroot/module-build'...
$ git fetch origin b2b23da8015cc6f2debf3d34a6457ea00e36c19e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/module-build
 * [new ref]         b2b23da8015cc6f2debf3d34a6457ea00e36c19e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2b23da Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild