Teaching sbuild how to use xdeb

[James Westby]

On Thu, 11 Nov 2010 17:32:06 -0200, Guilherme Salgado <salgado at canonical.com> wrote:
> > Oh, that looks interesting. I'm very keen to have a cross-autobuilder
> > churning through things to find out how much stuff actually
> > cross-builds at the moment.
> > 
> > In fact reading that work thing you seem to be wanting to build
> > exactly what I want to build: a system that repeatably builds
> > packages in pristine chroots. I thought sbuild didn't normally do the
> > pristine chroot thing? (which is why I've been using pbuilder to
> > supply that functionality to date).

We want to enable people to testbuild packages in a chroot. That may be
a building block that you can make use of to set up an autobuilder.

> Yeah, I don't think sbuild itself provides that, so I'm using schroot's
> type=file chroots for that.  You just point schroot to a tarball
> containing your chroot and it will (by default) create a new session
> (with a pristine chroot) every time you 'schroot -c <name>'.  If you
> want to change the contents of the tarball you can easily do that with
> 'schroot -c <name>-source'.  All you need for that to work is the
> following config:
> 
>         [natty]
>         description=Natty chroot
>         type=file
>         file=/var/chroots/natty.tar
>         location=/natty

That's one way of using it. I believe that if you just use a plain
chroot type then sbuild will attempt to remove the build-dependencies it
installed at the end of its run (obviously this is less reliable).

> > I think there is a better way, as largely elaborated above: give
> > sbuild a cross-dep resolver, use apt to install things of the
> > appropriate arch, passed through dpkg-cross if no multiarch version of
> > package available. And just issue dpkg-buildpackage -a<arch>
> > to do cross-builds. 
> 
> That sounds fine as well, and it's definitely more appealing given that
> we should be able to share at least parts of the new tools/libraries we
> develop.

sbuild already understands something about architectures, as you can
e.g. do -ai386 on an amd64 system, and it will do the right
thing. Perhaps it just needs this extending to handle cases where it
should cross-build, and use an appropriate dep-solving algorithm and
toolchain.

Also of interest is

  http://lists.debian.org/debian-devel/2010/11/msg00170.html

Would that change allow us to piggyback on any other work for the
cross-dep-solving, or would that basically require multi-arch to be
implemented?

Thanks,

James