Bug#1065831: apt tries to uninstall kde & plasma (full-upgrade)

[Miguel Angel Rojas <mianrojas@gmail.com>]

Hi Wesley,

Good conversation here. Let me give you some comments from my side:

> No, there is (or was) something going on with the dependencies of gdm-minimal
> for sure. I think it is related to libdebuginfod1, which has a t64 variant.
> This one has a dependency to libelf1 and libdw1. Now the libdebuginfod1t64
> depends on libelf1t64 and libdw1t64. These two replace libelf1 and libdw1, the
> former having a relative high count of reverse dependencies.

I didn’t catch this one (and I spent a fair amount of time trying to find out what was going on) ;) Thank you for spotting it!

> I do not know, at times I'm also wondering why it doesn't do it, but I didn't
> take time to look at the code to understand what the resolver is doing. Also,
> it was sort of expected. I think we can probably solve this is a more
> controlled manner. With the current t64 transitioning in unstable it is
> difficult to track down. Many updates so the situation now may differ from the
> situation in an hour from now.

Yes, it is confusing for me too. Without considering this t64 migration, “apt upgrade” should *NOT* remove any package (just upgrading a package to a newer version or install new dependencies). But it is removing packages right now! i.e. again, with this t64 migration, it makes the old libraries to be uninstalled and install the new *t64 version.

Any thoughts why “apt upgrade” is removing packages even when documentation says it shouldn’t? or is it a bug?

> I disagree (or agree) to some extent. The gdb-minimal has been held back on my
> system for a long time. I removed it after I saw it was a remnant of a KDE
> experiment I did. The fact that I can install it now is a change from a couple
> of days ago. The bug may be the same, but with how unstable it is now with
> this big transition, it's wise to leave it where we are now and break it down
> into a more controlled reproduction path, where we don't have so many moving
> pieces.

Yes, I fully agreed with that! Let’s wait until packages are fully settled down. I have a feeling that it is the same bug but there is no way to probe it with this transition going on.

Regards

On Mon, Mar 11, 2024 at 3:04 PM Wesley Schwengle <wesley@schwengle.net> wrote:

Hello Miguel,

On Mon, Mar 11, 2024 at 09:50:12AM +0100, Miguel Angel Rojas wrote:

> >This problem isn't because of apt, the problem is that gdb-minimal/gdb
> >  dependencies cannot be satified. A full-upgrade is the equivalent of a
> >  dist-upgrade which will remove packages to resolve the dependencies. The
> > problem you are facing is the t64 transition[1][2] where not all packages
> are
> >  transitioned.
>
> I haven't detected any "gdb | gdb-minimal dependencies that can't be
> satisfied at this point. Everything seems to be OK with those packages.

No, there is (or was) something going on with the dependencies of gdm-minimal
for sure. I think it is related to libdebuginfod1, which has a t64 variant.
This one has a dependency to libelf1 and libdw1. Now the libdebuginfod1t64
depends on libelf1t64 and libdw1t64. These two replace libelf1 and libdw1, the
former having a relative high count of reverse dependencies.

> >  My advice to you is: don't expect full-upgrade to work until the
> transitioning
> >   is done.
>
> You nail it here! I have managed to upgrade package by package but it is a
> tedious process until the whole transition is completed.

Some of them yes, but often after doing one, you can use `apt upgrade' to
see if it resolved other problems (which in my case it does from time to time).

> But "apt upgrade"
> should not remove any packages according to its documentation (man apt)

That is correct, but you were executing full-upgrade:

> > On Sun, Mar 10, 2024 at 02:13:34PM +0100, Miguel Angel wrote:
> >
> > > # apt full-upgrade
> > > Reading package lists... Done
> > > Building dependency tree... Done
> > > Reading state information... Done
> > > Calculating upgrade... Error!
> > > Some packages could not be installed. This may mean that you have
> > > requested an impossible situation or if you are using the unstable
> > > distribution that some required packages have not yet been created
> > > or been moved out of Incoming.
> > > The following information may help to resolve the situation:

> Why is this t64 upgrade working then as it is removing deprecated packages
> for *t64 packages?

I do not know, at times I'm also wondering why it doesn't do it, but I didn't
take time to look at the code to understand what the resolver is doing. Also,
it was sort of expected. I think we can probably solve this is a more
controlled manner. With the current t64 transitioning in unstable it is
difficult to track down. Many updates so the situation now may differ from the
situation in an hour from now.

> >  This seems to be an more of an actual issue where dependencies are
> declared but
> >    apt doing something weird. But that is an issue on bookworm where we
> aren't
> >    getting poluted results because of a transitioning.
>
> I'm glad you were able to replicate in bookworm (stable) it but I don't
> think (at least in this case) it is related to the t64 transition. Same
> errors on both distributions and I checked that gdb dependencies were
> satisfied in unstable (I don't have a system running stable).

I disagree (or agree) to some extent. The gdb-minimal has been held back on my
system for a long time. I removed it after I saw it was a remnant of a KDE
experiment I did. The fact that I can install it now is a change from a couple
of days ago. The bug may be the same, but with how unstable it is now with
this big transition, it's wise to leave it where we are now and break it down
into a more controlled reproduction path, where we don't have so many moving
pieces.

> Appreciate your support.

Yw and good luck!

Cheers,
Wesley