tb-updater failing during Qubes build process

[adrelanos]

Build QubesOS/updates-status#4080 was failing for mysterious reasons.

The last build succeeded. (With verbose mode enabled, which cannot become the final package version.)

Did anything related to build machine setup change?

It's a bit difficult to get to the button of of this. I was never able to reproduce this locally. Making a change and then issuing a new build command isn't very productive.

Only happening on this build server. Can you run manually commands on the server to simulate the environment? Or some other suggestion so I can iterate and test faster?

I disabled use of /usr/libexec/helper-scripts/curl-prgrs. Maybe something curl-prgrs does with streams (stdout, stderr) gets disrupted?

By carefully reading curl man page option --max-filesize one can conclude that it doesn't protest against an endless data attack (as described in the TUF threat model). curl-prgrs provides a nice progress bar (useful in terminal, not so much during Qubes build process) as well as environment variable CURL_PRGRS_MAX_FILE_SIZE_BYTES that can be used to prevent an endless data attack (or remote server bug). So I'd hope the functionality of curl-prgrs (progress bar + endless data attack/bug defense) can be kept. Replacing curl-prgrs with a more elegant and less code solution would be fine but that's hard, unrealistic.