$ git clone -n https://src.fedoraproject.org/rpms/libgda.git /var/lib/mock/f39-build-1651964-40495/root/chroot_tmpdir/scmroot/libgda
Cloning into '/var/lib/mock/f39-build-1651964-40495/root/chroot_tmpdir/scmroot/libgda'...
$ git fetch origin 4b8643d0ca2fbbd6579b1206110a151326ce3c9a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libgda
 * [new ref]         4b8643d0ca2fbbd6579b1206110a151326ce3c9a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4b8643d Fix FTBFS