hi. Thanks for the hint. It seems that the server has been generating the diffs all along;the but the client did not know about it.
Try to add these 4 lines to /etc/debdelta/sources.conf [debug debian archive] Origin=Debian Label=Debian debug delta_uri=http://debdeltas.debian.net/debian-debug-deltas a.
signature.asc
Description: OpenPGP digital signature