Re: What is /var/apt/cache good for ? (and other Sid dist-upgrade riddles)

[Greg Wooledge <wooledg@eeg.ccf.org>]

On Fri, Sep 15, 2017 at 03:02:50PM +0200, Thomas Schmitt wrote:
> When looking for the reason of the waste i got to nearly 5 GB of
>   /var/cache/apt
> 
> Before i run apt-get commands from the web like "clean" or "autoclean",
> i'd like to know for what use case Debian keeps this wealth of .deb files.

Let's say you're courageous enough to run testing or unstable.  You
upgrade a package, and something breaks.  Now you'd like to revert to the
previous version (after filing a bug report against the broken package,
of course, because that's WHY you are running testing or unstable in
the first place).

Luckily for you, the older version of the package is still sitting in
your /var/cache/apt/archives/ directory, so you can just go install
that and your problem is resolved.  Unless of course the package
performed some irreversible step upon upgrading to the broken version.
But hey, you're aware of the risks.  You're bold and intrepid and you
know your way around Debian.  That's why you dared to run testing or
unstable.