Swupd curl improvements

Developer Discussion
1

Hi! we have some remote systems with very slow and bad links. I see that swupd downloads fail.
(its not downloading from the public mirror, but from a private one)

{ “type” : “debug”, “msg” : “Curl - process_curl_error_codes - curl_ret = 92” },
{ “type” : “error”, “msg” : “Curl - Download error - (92) Stream error in the HTTP/2 framing layer” },

There seem to be some discussions, like

If I see the behaviour right the curl used in swupd is not resuming.

Is there an option to override that? I would like it to resume.

I tried to run it with
killall swupd ; swupd update -r100 -d0 -t --debug -j --download -W1|tee -a hostname-date -Isec-swupd-update.log

but it does not manage to download the 200+mb file before it fails and retries (now reaching the 100 retry limit.

One option I see is to rsync the files over (which seem to be as slow but stable) to /var/lib/swupd/cache/
Is there a way to identify the files which are needed for the next download step?

Also wget seems to be more robust than curl.

Or any other suggestions how to get the system up to the latest version?

(it is behind some formats, so also some fast tracking option from an old format to the latest would be an interesting thing)

PS: in --debug mode it would be handy to add timestamps, even the -t did not fix that