Re: Is anyone looking at apt bugs affecting cross-dependencies?
+++ David Kalnischkies [2012-05-11 21:39 +0200]:
> On Fri, May 11, 2012 at 6:59 PM, Wookey <wookey@wookware.org> wrote:
> > This apt bug is blocking a lot of cross-builds low in the stack.
> > I'm just wondering if it is on anyone's radar and if so how much
> > work they feel is involved and when it might get done? If not can
> > someone give me some clue as to which bit of code might be involved
> > (but I am utterly clueless about apt internals - it's probably eaier
> > to fix it than explain to me what to look at)
> >
> > https://bugs.launchpad.net/ubuntu/+source/apt/+bug/970050
>
> I will give it a look next week than i am back from UDS.
>
> Launchpad-bugs tend to hide themself between Expires and random
> machine-related segfaults, so at least for me they are quiet easy
> to miss. Feel free to report them in the BTS, i personally tend to
> monitor this way more closely, even if not ever bug gets an respond.
Yes. I expected there to already be a corresponding bug in the BTS,
but it seems there isn't. Having just checked that is presumably
because this bug is rather less obvious in Debian unstable, than in
Ubuntu precise/quantal, presumably due to other aspect of the
multi-arch dependency tree.
I've filed a bug now:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=672927
It's pretty easy to reproduce the problem, and hopefully very easy to
fix if you know where to look.
> > Also, considering bootstrapping. I have a noddy patch to make apt
> > not-complain about the extra headers
> > (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=661537 ) but for
>
> It complains? Really?
> Without looking at the code it should just ignore these files and
> that should be fine as it doesn't support stages anyway.
Hmm, OK. I'm pretty sure I had to patch it due to some bitching, and
didn't just do it for fun. But I can't remember now. I'll check.
> > apt-get build-dep <package> to do the right thing for bootstrapping it
> > needs to read Build-Depends-StageN instead of Build-Depends for
> > <package> then do whatever it normally does. Again, some idea of how
> > much work this is (hopefully not much, but I could be wrong), and
> > clues where to look in the code would be very helpful.
>
> It's in cmdline/apt-get.cc method DoBuildDep(), but to read other files
> we need to change the sources parser
There should be no need to read in other files (except as directed
by deb-src lines in the usual way).
> So it shouldn't be that hard to do… (famous last words).
Great :-)
> Slightly related: If you have pointers to documentation on how someone
> is supposed to be able to crossbuild, sharing would be nice.
> As said, i haven't really touched crossbuilding so far…
Useful docs on multiarch crossbuilding:
This is how to set up an sbuild cross-chroot
https://wiki.linaro.org/Platform/DevPlatform/CrossCompile/UsingMultiArch
If you don't want to set it all up in a chroot then this is a simpler
doc:
http://suihkulokki.blogspot.co.uk/2012/04/cross-compiling-with-multiarch-congrats.html
And I just knowcked-up a non-crossbuilding Multiarch HOWTO as I
couldn't see one elsewhere:
http://wiki.debian.org/Multiarch/HOWTO
Do check the apt bits are right - especially versions when things
started working. Or anything else users regularly ask about multiarch.
Wookey
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