Bug#1070706: gtk4 udeb has unsatisfiable dependencies

[Cyril Brulebois]

Hi Simon,

Simon McVittie  (2024-05-07):
> Looking at the d-i Packages.gz for amd64, the only other source
> package that has picked up the bad libpng16-16t64-udeb dependency
> seems to be matchbox-keyboard, which needs a sourceful upload to fix an
> implicit-declarations FTBFS anyway, therefore isn't useful to binNMU.

Yeah, I forgot to mention it when I worked on making d-i buildable and
runnable again, then decided it didn't matter as it's not used (TTBOMK)
at the moment.

> After that: do the release/installer teams consider udeb dependencies
> on non-udeb packages, by udebs that d-i does not currently need or use,
> to be a RC issue or merely a nice-to-have?

If udebs are actually used, I call that an RC bug and try to get it
fixed swiftly (sometimes NMUing right away when time is of the essence).
Otherwise I usually let those fly (without even filing bug reports).

See: https://d-i.debian.org/dose/
Some backstory: https://lists.debian.org/debian-boot/2024/03/msg00102.html


Cheers,
-- 
Cyril Brulebois (k...@debian.org)
D-I release manager -- Release team member -- Freelance Consultant


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Bug#1070706: gtk4 udeb has unsatisfiable dependencies

[Simon McVittie]

Control: severity 1070706 normal
Control: severity 1070714 normal

On Tue, 07 May 2024 at 22:53:33 +0200, Cyril Brulebois wrote:
> Simon McVittie  (2024-05-07):
> > do the release/installer teams consider udeb dependencies
> > on non-udeb packages, by udebs that d-i does not currently need or use,
> > to be a RC issue or merely a nice-to-have?
> 
> If udebs are actually used, I call that an RC bug and try to get it
> fixed swiftly (sometimes NMUing right away when time is of the essence).
> Otherwise I usually let those fly (without even filing bug reports).

In that case I'm downgrading #1070714 and #1070706 to normal, because the
issues I noticed while investigating #1070706 are worth tracking and being
aware of but non-RC, and the issue that Peter originally reported is not
actionable for the gtk4 maintainers (it needs to be fixed via a binNMU).

We'll need to revisit #1070714 and #1070706 if someone makes a concerted
effort to GTK3ize the installer, but that has been on my to-do list since
before bookworm and shows no signs of approaching the top, so it might
have to be someone else's project.

Thanks!

smcv

Bug#1070706: gtk4 udeb has unsatisfiable dependencies

[Simon McVittie]

On Tue, 07 May 2024 at 22:02:12 +0200, Paul Gevers wrote:
> On 07-05-2024 7:49 p.m., Simon McVittie wrote:
> > The version in testing, 4.12.5+ds-3, has the same dependencies, so this
> > is not a regression.
> 
> Is it? It seems that the version in unstable depends on libpng16-16t64-udeb
> where the version in testing depends on libpng16-16-udeb. The later exists,
> the former not.

Oh, well spotted! It looks as though src:gtk4 needs a binNMU against
libpng-dev (>= 1.6.43-4) for #1066069, because we were unlucky with
the timing of gtk4's most recent upload and so it got built against the
incorrect libpng-dev.

My understanding is that a binNMU would be better than a sourceful upload
of gtk4 because it won't reset the migration clock. If that's correct,
please could someone with release team or wanna-build powers schedule it?

nmu gtk4_4.12.5+ds-6 . ALL . -m 'rebuild with #1066069 fixed'

Looking at the d-i Packages.gz for amd64, the only other source
package that has picked up the bad libpng16-16t64-udeb dependency
seems to be matchbox-keyboard, which needs a sourceful upload to fix an
implicit-declarations FTBFS anyway, therefore isn't useful to binNMU.

After those binNMUs, the gtk4 udeb will still not be installable into
the debian-installer environment (either in testing or in unstable), but
it should at least be able to migrate, because all of its dependencies
will be packages that exist (whether deb or udeb).

After that: do the release/installer teams consider udeb dependencies
on non-udeb packages, by udebs that d-i does not currently need or use,
to be a RC issue or merely a nice-to-have?

Thanks,
smcv

Bug#1070706: gtk4 udeb has unsatisfiable dependencies

[Paul Gevers]

Hi,

On 07-05-2024 7:49 p.m., Simon McVittie wrote:

The version in testing, 4.12.5+ds-3, has the same dependencies, so this
is not a regression.


Is it? It seems that the version in unstable depends on 
libpng16-16t64-udeb where the version in testing depends on 
libpng16-16-udeb. The later exists, the former not.



Is this requirement newly enforced by britney?


No.

Paul


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Bug#1070706: gtk4 udeb has unsatisfiable dependencies

[Simon McVittie]

Control: tags -1 + d-i
Control: found -1 4.12.5+ds-3
Control: retitle -1 gtk4 udeb has unsatisfiable dependencies
Control: clone -1 -2
Control: retitle -2 libvte-2.91-0-udeb depends on both GTK 3 and GTK 4
Control: reassign -2 src:vte2.91 0.75.92-1

On Tue, 07 May 2024 at 15:44:02 +0100, Peter Michael Green wrote:
> According to britney, gtk4's udebs are uninstallable.

gtk4 is not yet used by debian-installer (which is still on GTK 2)
so the udeb is not actually necessary, and one workaround would be to
disable it entirely (but then we'd have to put GTK 4 through NEW again
if we are ever able to upgrade d-i to it).

The version in testing, 4.12.5+ds-3, has the same dependencies, so this
is not a regression. Is this requirement newly enforced by britney?

I think a large part of the problem is that when GTK 4 support was added
to src:vte2.91, both the GTK 3 and GTK 4 versions were put into the same
udeb package, libvte-2.91-0-udeb, instead of giving the GTK 4 version
its own udeb. However, I'm unsure how that change got into testing -
if britney is enforcing installability of udebs, I would have expected
that the updated libvte-2.91-0-udeb would have been newly-uninstallable,
preventing its migration?

It seems most realistic that d-i in Debian 13 will depend on GTK 3 if
someone finds the time to do the necessary porting and testing, or stay
on GTK 2 if not, so libvte-2.91-0-udeb should become a udeb version of
only libvte-2.91-0 (i.e. GTK 3 only) as it was in Debian 12, and drop
its GTK 4 parts. That would mean that GTK 4 would no longer be regressing
the installability of libvte-2.91-0-udeb.

If there is a serious attempt to get d-i using GTK *4*, then that would
require a new libvte-2.91-gtk4-0-udeb. However, GTK 4's threading model
is definitely incompatible with the current design of cdebconf-gtk (it
calls into GTK from more than one thread, which is discouraged in GTK
3 and not allowed at all in GTK 4), so a prerequisite for that would
be to move all of cdebconf-gtk's GTK interactions onto one thread,
with message-passing between that thread and the cdebconf thread.

I'm also unsure how GTK 4 can possibly have caused libvte-2.91-0-udeb's
installability to regress anyway, because libvte-2.91-0-udeb in testing
depends on liblz4-1, which does not have a corresponding udeb. That
will need fixing (by adding a liblz4-1-udeb, or linking it statically,
or allowing .deb libraries to satisfy udebs' dependencies) if we ever
want a GTK 3 or later installer.

Making the GTK 4 udeb installable looks like a significant task. It depends
on:

OK - fontconfig-udeb (>= 2.15.0),
OK - libc6-udeb (>= 2.37),
!! - libcairo-script-interpreter2 (>= 1.18.0),
OK - libcairo2-udeb (>= 1.18.0),
OK - libepoxy0-udeb (>= 1.5.4),
OK - libfribidi0-udeb (>= 1.0.13),
OK - libgdk-pixbuf-2.0-0-udeb (>= 2.42.10+dfsg),
OK - libglib2.0-udeb (>= 2.78.4),
!! - libgraphene-1.0-0 (>= 1.10.8),
OK - libharfbuzz0-udeb (>= 8.3.0),
!! - libjpeg62-turbo (>= 1:2.1.5),
OK - libpango1.0-udeb (>= 1.52.1+ds),
OK - libpng16-16t64-udeb (>= 1.6.2),
!! - libtiff6 (>= 4.5.1+git230720),
OK - libx11-6-udeb (>= 2:1.6.0),
OK - libxcursor1-udeb (>> 1.1.2),
!! - libxdamage1 (>= 1:1.1),
OK - libxext6-udeb (>= 2:1.3.0),
OK - libxfixes3-udeb (>= 1:5.0),
OK - libxi6-udeb (>= 2:1.6.99.1),
OK - libxinerama1-udeb (>= 2:1.1.4),
OK - libxrandr2-udeb (>= 2:1.5)

cairo has a udeb, but it doesn't include the equivalent of
libcairo-script-interpreter2. It might be possible to disable the GTK
features that rely on that library? Or it might be possible to add the
script interpreter to the udeb?

graphene does not have udebs at all, and I think it's a mandatory
dependency for GTK 4, so if we ever want a GTK-4-based d-i, there is
no avoiding adding a graphene udeb.

libjpeg-turbo, tiff and libxdamage are in the same situation as graphene
(these were optional in GTK 3 but are required in GTK 4). Unlike graphene,
these are not maintained by the GNOME team, so we cannot unilaterally
add udebs to them.

smcv