Bug#1108193: apt: Ordering issue with libc6:i386 on amd64-m-a system breaks partial upgrade ("just apt and dpkg") from bookworm to trixie

On Mon, Jun 23, 2025 at 04:58:34PM +0200, Helmut Grohne wrote:
> On Sun, Jun 22, 2025 at 11:05:03PM +0200, Helmut Grohne wrote:
> > mmdebstrap --variant=apt --architectures=amd64,i386 --include=systemd-timesyncd,libc6-dbg:i386 --chrooted-customize-hook='sed -i -e s/bookworm/trixie/ /etc/apt/sources.list && apt update && apt-get -y install apt' bookworm /dev/null
> 
> Further observations.
>  * We may install libc6 instead of apt.
>  * We may include systemd-container instead of systemd-timesyncd.
>  * If we include systemd-resolved or systemd-boot instead of 
>    systemd-timesyncd, the problem does not reproduce.
>  * trixie's libc6 Breaks: system (<< trixie).
>  * trixie's systemd Pre-Depends: libsystemd-shared (= ...)
>  * trixie's libsystemd-shared Depends: libc6 (>= trixie)
>  * All of systemd-container, systemd-resolved, systemd-boot and 
>  * systemd-timesyncd Conflicts: systemd (<< trixie).
>  * In the apt log you may see that apt unpacks libsystemd-shared and 
>    only then considers deconfiguring systemd (which Depends: 
>    libsystemd-shared (= ...)). Why is that legal?


I do not have the time to investigate this in the foreseeable
future. I may be able to get into it at DebCamp.

That being said, it's entirely possible there is a loop here,
and APT breaks the loop in a way dpkg isn't happy about; this
also doesn't neccessarily have to be "legal". It's more "there
is no correct solution, but we don't want to give up, so we do
random shit".

-- 
debian developer - deb.li/jak | jak-linux.org - free software dev
ubuntu core developer                              i speak de, en