Felix Miata composed on 2020-06-18 21:48 (UTC-0500):
Does Debian have any kind of configuration option that can make 'apt upgrade' try harder to download all packages instead of all except one that for whatever mirror failure reason fails, and halting the upgrade process because that one file didn't download? It seems typical here that one package, any package, isn't found on the trinity mirrors on the first pass, but on second invocation of apt upgrade, that one package is fetched, and the entire apt upgrade continues to completion.
The latest case was just now, sb on Bullseye:
libkexiv2-3-trinity-14.0.8-0debian11.0.0+0~a_amd64.deb
This just happened with Mageia 7 with 2 packages, trinity-tdelibs & lib64avahi-tqt1, the former going from 14.0.7 to 14.0.9, apparently having happened before but ignored by me.
To recap, all other packages were fetched on first 'urpmi --auto-select', but the two failed, and were successfully fetched simply by rerunning 'urpmi --auto-select'.