Re: Bug#987017: recommends 3 different ways to find obsolete packages, pick one
On Fri, Apr 16, 2021 at 09:19:35AM +0100, Justin B Rye wrote:
>
> # 4.2.2. Remove non-Debian packages
> #
> # Below there are two methods for finding installed packages that did
> # not come from Debian, using either aptitude or apt-forktracer.
> # Please note that neither of them are 100% accurate (e.g. the
> # aptitude example will list packages that were once provided by
> # Debian but no longer are, such as old kernel packages).
>
> Now that you come to mention it I've always thought that was a bad
> example, since after all it isn't exactly a false-positive - old
> linux-images really are no-longer-Debian packages, and if you've got
> some lying around even before the upgrade, this would be an
> appropriate time to get rid of them, as we go on to say a little
> later.
Old kernels are sometimes kept around as a kind of backstop in
case a new kernel turns out not to work properly.
...
...
>
> Yes, but how do you come to be running a system with non-Debian
> repositories in your sources and installing packages to inspect the
> gory details without already realising you've done that?
You may have forgotten.
You may have long ago enabled a nonDebian repository to install some
nonDebian package. Unbeknownst to you, that repository also contained
variants of debian packages which ended up replacing the Debian packages
you expected to keep.
A real mess. They look like Debian packages, but they are not.
Th the extent that the new packages have more recent version numbers than
the intruding packages, things may still go well.
>
> Now that we've got "https://deb.debian.org/debian/";, we're close to
> being able to say that standard procedure is "for the duration of the
> upgrade, comment out any lines that don't match that URL".
Sounds like a valid thing to do, anyway.
-- hendrik
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