$ git clone -n https://src.fedoraproject.org/rpms/xar.git /var/lib/mock/f38-build-side-42-init-devel-1369020-30706/root/chroot_tmpdir/scmroot/xar
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1369020-30706/root/chroot_tmpdir/scmroot/xar'...
$ git fetch origin 07a12d7033513fa210a12de0b3bb3d2489f44c9e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xar
 * [new ref]         07a12d7033513fa210a12de0b3bb3d2489f44c9e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 07a12d7 Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild