/var/cache/apt/archive persistence

[jimbolaya]

I recently upgraded something on my machine and the new version is failing. I wanted to go check if the older version would still work in case I missed something. I found that the newest files in /var/cache/apt/archive were from August. It's entirely possible I missed that there was a change in behavior that debs would no longer be saved or that I may have inadvertently change the behavior myself, but now, if that's changed, I would like that setting back.

It's not obvious to me where to set that. Is there documentation on this somewhere?