Bug#1078608: apt update silently leaves old index data

[Clément Hermann <nodens@debian.org>]

Hi there,

I've been having the same issue on a laptop.

In my case, the issue seems to have been that apt was interrupted 
(possibly a sudden shutdown due to empty battery) after the InRelease 
file was downloaded but before the the actual Packages files where updated.

So, since the InRelease file was up to date, no list was checked and the 
obsolete ones where used.

Removing the InRelease file fixes the issue in this case.

It would be nice if APT could validate that the Package lists have 
actually been checked based on the current InRelease info, so that if 
this happen (interruption at a bad time), it checks the individual lists 
files even if the InRelease is unchanged.

Another thing that could help would be a configuration option or a 
specific command to revalidate lists, something one could run routinely 
e.g once a month to avoid missing updates, or even a systematic 
validation of lists even though it can take more time when one uses 
compression - I would accept consuming a bit more CPU time and power to 
make sure systems are up to date, even if that's not the default.

Cheers,

--
nodens