Comment 7 for bug 674346

Did some more testing. Perhaps Corey's and my installations don't differ after all.

On 10.04, changing the "Temporary Files" option to "Delete downloaded packages after installation" in the Synaptic preferences affects *both* Synaptic itself and Update Manager. (Verified by changing it to "Leave all downloaded packages in the cache" and fetching some updates, then setting it back and fetching more updates.)

On 11.04 (at least), the Synaptic setting only affects packages installed through Synaptic; Update Manager always leaves the packages in the cache.

(For completeness, on neither version does the Synaptic setting affect the behaviour of "sudo apt-get install", which leaves stuff lying around in the cache regardless.)

Perhaps one might reasonably expect the Synaptic setting to only affect Synaptic. However, it's a regression in behaviour compared to 10.04, and it leaves no obvious way for users to stop /var/cache/apt/archives growing without bounds due to security and other updates (since Update Manager doesn't have its own preference for this).

Perhaps I can fix this by creating/editing /etc/apt.conf, but I think there should be an easier way. The 10.04 behaviour seems a fine way of configuring this to me.

(Leaving the packages lying around is a silly default anyway. http://brainstorm.ubuntu.com/idea/16215/ reflects this, but the idea of fixing it seems to have run out of steam.)