$ git clone -n https://src.fedoraproject.org/rpms/vecgeom.git /var/lib/mock/f42-build-862904-171231/root/chroot_tmpdir/scmroot/vecgeom
Cloning into '/var/lib/mock/f42-build-862904-171231/root/chroot_tmpdir/scmroot/vecgeom'...
$ git fetch origin 4af4af4e1c745a8b04e49b8a34fd67d5a296cde5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vecgeom
 * [new ref]         4af4af4e1c745a8b04e49b8a34fd67d5a296cde5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4af4af4 Rebuild for xerces-c 3.3