Bug#1107108: pre approval sbuild

[Ivo De Decker <ivodd@debian.org>]

Hi,

On Sun, Jun 01, 2025 at 10:15:29PM +0200, Aurelien Jarno wrote:
> > > this is a pre approval request for an sbuild upload.
> > > 
> > > I would like to improve the build environment for forky by cleaning the
> > > apt cache before running dpkg-buildpackage. This has the advantage that
> > > we have a better definition of the build environment which makes it
> > > easier to reproduce it with debrebuild later. josch (for sbuild) and
> > > Aurelien (for wanna build) signaled already that they would be fine with
> > > this.
> > >
> > > Note that we only want to enable this in forky but I would still like to
> > > push this to trixie for one because it makes it easier to implement this
> > > on the buildds and two Debian developers using stable would get the same
> > > results as on the buildds.
> > 
> > I understood that the change was limited to forky and later. With this 
> > change applied and migrated to trixie this technically makes the bugs 
> > below RC.
> > 
> > > Santiago Vila did a rebuild of unstable and reproduce.debian.net tested
> > > trixie so we are pretty sure that there are only three packages that
> > > would need patching with this feature: autodep8 (#961138), dh-r
> > > (#1089197) and blends (#1104515). All of them have proposed patches
> > > already. Note that I don't propose to apply them for trixie.
> > 
> > One option is to accept this change, but with the default set to 1 
> > (don't clean). Then we can pass the option to sbuild on the buildds for 
> > forky/sid/experimental once trixie is released. And developers can also 
> > manually use that option to reproduce the buildds behavior. 
> > Alternatively the behaviour can be changed only for >= forky in the 
> > first point release.
> 
> After discussion with Jochen on IRC, a better option would be to let 
> this patch enter trixie, but then explicitly disable apt cleaning on the 
> buildds for trixie. We just need to synchronize the migration to testing 
> and the changes to the buildds.

As we are now in the hard freeze, I feel not changing the default behavior in
trixie seems like the most logical way forward. It gives the smallest risk of
regressions. It still leaves the option to change the config on the buildds.

Feel free to clarify the reason why you would want to change the default in
trixie.

Thanks,

Ivo