[buildd-tools-devel] Bug#697549: sbuild-createchroot adds the host arch as a foreign arch in a foreign chroot

[Ian Campbell]

Package: sbuild
Version: 0.63.2-1
Severity: normal

I'm using sbuild with foreign chroots via qemu-*-static as described in[0].
I've noticed that in my armel and armhf chroots amd64 is present as a foreign
arch within the chroot.

This means that when sbuild does the apt update/upgrade dance it is
downloading/uncompressing/processing a second set of architecture package lists
using the emulated binaries. It would be better to avoid such unnecessary work
in this case because of the emulation overheads. I've also got amd64 as a
foreign arch in my i386 chroot but that is less of a worry.

The foreign arch configuration doesn't appear to be added (i.e. it is already
there) when I run "sbuild  --arch=armel" and I've found that it is present in
the source chroots too. I logged into the source chroot and "dpkg
--remove-architecture amd64" and it is not added back by sbuild. I think that
sbuild-createchroot must have added it.

sbuild-createchroot uses Sbuild::AptResolver, I wonder if it could be that via
an interaction with c89125965a15 "Sbuild::ResolverBase: Configure dpkg
foreign-architecture"? sbuild-createchroot seems to set HOST_ARCH but not
TARGET_ARCH and the distinction between the two is is used in that changeset.

I'm running 0.63.2-1 but I can't see any change in the git tree which seems
relevant.

I've been round all my chroots and run dpkg --remove-architecture and AFAICT
things seem OK (although I've only tried one or two builds).

Ian.

[0] http://www.hellion.org.uk/blog/posts/foreign-chroots-with-schroot-and-qemu/

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'stable-updates'), (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages sbuild depends on:
ii  adduser         3.113+nmu3
ii  apt-utils       0.9.7.6
ii  libsbuild-perl  0.63.2-1
ii  perl            5.14.2-15
ii  perl-modules    5.14.2-15

Versions of packages sbuild recommends:
ii  debootstrap  1.0.42
ii  fakeroot     1.18.4-2

Versions of packages sbuild suggests:
ii  deborphan  1.7.28.8
ii  wget       1.13.4-3

-- no debconf information