Dpkg with multiarch support available in Debian experimental

As I announced on debian-devel, Guillem Jover uploaded a snapshot of dpkg’s multiarch branch to experimental (version 1.16.2~wipmultiarch). Beware: There will
likely be some small “interface” changes between this version and the version that will be released later in unstable (possibly in the output of dpkg --get-selections, dpkg --list, maybe other commands).

multiarch allows you to install packages from different architectures on the same machine. This can be useful if your computer can run programs from 2 architectures (eg. x86 CPU supporting i386 and amd64), or if you often need to cross-compile software and thus need the libraries of your target architecture.

Test dpkg with multiarch support

If you want to test multiarch support in dpkg, install the package from experimental (apt-get install dpkg/experimental assuming you have experimental in your sources.list).

Then you can add a supplementary architecture to your system by doing sudo dpkg --add-architecture <arch> (e.g. i386 if you are on amd64, and vice-versa). APT will automatically pick up the new architecture and start downloading the Packages file for the new architecture (it uses dpkg --print-foreign-architectures to know about them).

From there on you can install packages from the “foreign” architectures with “apt-get install foo:<arch>“. Many packages will not be installable because some of their dependencies have not yet been updated to work with in a multiarch world (libraries must be installed in a multiarch-compliant path so as to be co-installable, and then marked “Multi-Arch: same“). Other dependencies might need to be marked “Multi-Arch: foreign“. See wiki.debian.org/Multiarch/Implementation for more HOWTO-like explanations.

Now is a good time to see if you can install the foreign packages that you could need in such a setup and to help to convert the required libraries.

You can also read Cyril Brulebois’ article which quickly shows how to hunt for the problematic packages which have not been converted to multiarch (in his sample, “ucf” is not ready. Since it’s an “Architecture: all” package which can run on any architecture, it means that it’s lacking a “Multi-Arch: foreign” field).

Report bugs

If you discover any bug in dpkg’s multiarch implementation, please report it to the Bug Tracking System (against “dpkg” with the version “1.16.2~wipmultiarch”).

If you notice important libraries or packages which are not yet multiarch ready, please open wishlist bug reports requesting the conversion and point the maintainers towards the wiki page linked above. Even better, prepare patches and submit those with your bug reports.

Again, you can follow the lead of Cyril Brulebois who filed 6 bugs!

Review the multiarch implementation

If you’re a C programmer and have some good knowledge of dpkg (or are willing to learn more of it), we would certainly benefit from more eyes reviewing the multiarch branch. If you want to discuss some design issues of the multiarch implementation in dpkg (or have questions related to your review), please get in touch via debian-dpkg@lists.debian.org.

The latest version of the branch is pu/multiarch/master in Guillem’s personal repository. I have my own version of the branch (pu/multiarch/full) which is usually a snapshot of Guillem’s branch with my own submitted fixes.

$ git clone git://git.debian.org/dpkg/dpkg.git
$ cd dpkg
$ git remote add guillem git://git.hadrons.org/git/debian/dpkg/dpkg.git
$ git remote add buxy git://git.debian.org/~hertzog/dpkg.git
$ git fetch guillem && git fetch buxy

If you followed the instructions above, the relevant branches are thus guillem/pu/multiarch/master and buxy/pu/multiarch/full. Both branches are regularly rebased on top of master where Guillem merges progressively the commits from the multi-arch branch as his review progresses.

Thank you in advance for your help bringing multiarch in shape for Debian Wheezy,

My Debian Activities in January 2012

This is my monthly summary of my Debian related activities. If you’re among the people who made a donation to support my work (213.68 €, thanks everybody!), then you can learn how I spent your money. Otherwise it’s just an interesting status update on my various projects.


The “biggest change” I made is a small patch that brings to an end years and years of recurring discussions about the build-arch and build-indep targets of debian/rules (see #229357). Last year the technical committee took this issue in its hands (see #629385) but it failed to take any resolution. Fortunately thanks to this we got some concrete numbers on the colateral damages inflicted on the archive for each possible approach. In the end, Guillem and I managed to agree on the way forward.

The remaining of what I did as dpkg maintainer has not much to do with coding. I reviewed the work of Gianluca Ciccarelli on dpkg-maintscript-helper who is trying to provide helper functions to handle migration between directories and symlinks. I also reviewed a 2000-lines patch from Patrick Schoenfeld who’s trying to provide a perl API to parse dpkg log files and extract meaningful data out of them.

I updated the dpkg-architecture manual page to document the Makefile snippet /usr/share/dpkg/architecture.mk and to drop information that’s no longer releveant nowadays.

I reviewed a huge patch prepared by Russ Allbery to update the Debian policy and document the usage of symbols files for libraries. As the author of dpkg-gensymbols, I was keen to see it properly documented at the policy level.

I brought up for discussion a detail that was annoying me for quite some time: some copyright notices were embedded in translatable strings and updating them resulted in useless work for translators. In the end we decided to drop those notices and to keep them only at the source level.

I updated my multiarch branch on top of Guillem’s branch several times, all the fixes that were in my branch have been integrated (often in a modified form).

Unfortunately even if the code works quite well, Guillem doesn’t want to release anything to Debian until he has finished to review everything… and many people are annoyed by the unreasonable delay that it imposes. Cyril Brulebois tried to release a snapshot of the current multiarch branch to experimental but Guillem has been prompt to revert this upload.

I’m somewhat at a loss in this situation. I offered my help to Guillem multiple times but he keeps doing his work in private, he doesn’t share many details of his review except some comments in commit logs or when it affects the public interface. I complained once more of this sad situation.

Debian Package Maintenance Hub

That’s the codename I use for a new infrastructure that I would like to develop to replace the Package Tracking System and the DDPO and several other services. I started to draft a Debian Enhancement Proposal (DEP), see DEP-2, and requested some comments within the QA team.

For now, it looks like that nobody had major objections on the driving idea behind this project. Those who commented were rather enthusiastic. I will continue to improve this DEP within the QA team and at some point I will bring the discussion to a larger audience like debian-devel@lists.debian.org.

Package Tracking System

Even if I started to design its replacement, the PTS will still be used for quite some time so I implemented two new features that I deemed important: displaying a TODO notice when there is (at least) one open bug related to a release goal, displaying a notice when the package is involved in an ongoing or upcoming transition.

Misc packaging tasks

I created and uploaded the dh-linktree package which is a debhelper addon to create symlink trees (useful to replace embedded copies of PHP/JavaScript libraries by symlinks to packaged copies of those files).

I packaged quilt 0.50. I helped the upstream authors to merge a Debian patch that had been forwarded by Martin Quinson (a quilt’s co-maintainer). I packaged a security release of WordPress (3.3.1) and a new upstream release of feed2omb and gnome-shell-timer.

I prepared a new Debian release of python-django with a patch cherry-picked from the upstream SVN repository to fix the RC bug #655666.

Book update

We’re again making decent progress in the translation of the Debian Administrator’s Handbook, about 12 chapters are already translated.

The liberation campaign is also (slowly) going forward. We’re at 72% now (thanks to 63 new supporters!) while we were only at 67% at the start of January.


See you next month for a new summary of my activities.

My Debian Activities in December 2011

This is my monthly summary of my Debian related activities. If you’re among the people who made a donation to support my work (364.18 €, thanks everybody!), then you can learn how I spent your money. Otherwise it’s just an interesting status update on my various projects.

Dpkg and Multiarch

I had some hope to have a multiarch-enabled dpkg in sid for Christmas as Guillem told me that it was realistic. Alas Guillem got sick. We’re in January and we’re still not there.

While some of Guillem’s commits in December were related to multi-arch, the size of his pu/multiarch/master branch did not really shrink. We still have 36 commits to merge… most of the work he did was refactoring some parts of the code that were already merged. And he initiated some discussion on interface changes. I participated to those discussions hoping to bring them to a quick resolution.

I’m still maintaining my own pu/multiarch/full branch, it is based on Guillem’s branch but with further fixes that I developed and that he has not yet merged and with a change reverted (Guillem’s branch allows crossgrading packages between different architectures while dpkg does not manage this correctly yet).

I can only hope that January will be the last month of this never-ending saga. It’s been one year since I started working on this project. 😐

Misc dpkg work

I reviewed (and later merged) a patch of Kees Cook to enhance dpkg-buildflags so that it can report which hardening features are enabled. This feature might then be used by tools like lintian to detect missing hardening features.

I mentored Gianluca Ciccarelli who is trying to enhance dpkg-maintscript-helper to take care of replacing a directory by a symlink and vice-versa.

I took care of #651993 so that dpkg-mergechangelogs doesn’t fail when it encounters an invalid version in the changelog, and of #652414 so that dpkg-source --commit accepts a relative filename when a patch file is explicitly given.

Guillem also merged a fix I developed for LP#369898.

Packaging work

WordPress 3.3 came out so I immediately packaged it. Despite my upstream bug report, they did not update their GPL compliance page which offers the corresponding sources for what’s bundled in the tarball. So I hunted for the required sources myself, and bundled them in the debian.tar.xz of the Debian source package. It’s a rather crude solution but this allowed me to close the release critical bug #646729 and to reintroduce the Flash files that were dropped in the past… which is great since the Flash-based file uploader is nicer than the one using the browser’s file field.

Quilt 0.50 came out after 2 years of (slow) development. The Debian package has many patches and several of them had to be updated to cope with the new upstream release. Fortunately some of them were also merged upstream. It still took an entire morning to complete this update. I also converted the packaging from CDBS to dh with a short rules file.

Zim 0.54 came out and I immediately updated the package since it fixed a bug that was annoying me.

Review of the ledgersmb packaging

As the sql-ledger maintainer (and a user of this software for my accounting), I have been hoping to get ledgersmb packaged as a possible replacement for it. I have been following the various efforts initiated over time but none of them resulted in a real package in Debian.

This is a real pity so I tried to fix this by offering to sponsor package uploads. That’s why I did a first review of the packaging. It took several hours because you have to explain everything that’s not good enough.

I also filed a wishlist bug against lintian (#652963) to suggest that lintian should detect improper usage of dpkg-statoverride (this is a mistake that was present in the package that I reviewed).

nautilus-dropbox work

I wanted to polish the package in time for the Ubuntu LTS release and since Debian Import Freeze is in January, I implemented some of the important fixes that I wanted.

The Debian package diverges from upstream in that the non-free binaries are installed in /var/lib/dropbox/ instead of $HOME.
Due to a bug, the files were not properly root-owned so I first fixed this (unpacking the tarball as root lead to reuse of the embedded user & group information, and those information changed recently on the Dropbox side apparently).

Then we recently identified other problems related to proxy handling (see #651065). I fixed this too because it’s relatively frequent that the initial download triggered during the package configuration fails… and in that case it’s the user that will re-trigger a package download after having given the appropriate credentials through PackageKit. Without my fix, usage of pkexec would imply the loss of the http_proxy environment variable and thus it would not be possible for a user to download through a proxy.

Last but not least I reorganized the Debian specific patches to better separate what can and should be merged upstream, from the changes that upstream doesn’t want. Unfortunately Dropbox insists on being able to auto-update their non-free binaries, they are, thus, against the installation under /var/lib/dropbox and the corresponding changes.

Book update

We’re making decent progress in the translation of the Debian Administrator’s Handbook, about 6 chapters are already translated (not yet reviewed though).

The liberation campaign is also (slowly) going forward. We’re at 67% now (thanks to 90 new supporters!) while we were only at 60% at the start of December.


See you next month for a new summary of my activities.

My Debian Activities in November 2011

This is my monthly summary of my Debian related activities. If you’re among the people who made a donation to support my work (310.73 €, thanks everybody!), then you can learn how I spent your money. Otherwise it’s just an interesting status update on my various projects.

Dpkg: Multi-Arch Saga

I know lots of people are waiting the landing of multiarch in Debian unstable, and so am I. Things are progressing, though not as quickly as I hoped. Guillem merged about half of the branch between the 24th October and the 6th of November. After that most of the work happened on his personal repository in his pu/multiarch/master branch.

I verify this repository from time to time because Guillem does not inform me when he has made progress. I noticed changes on his repository on the 10th, 19th, 23th, 28th of November and on the 1th of December.

He announced a long time ago that he had some “interface changes” and up to now only wrote about the switch from the command-line option --foreign-architecture (to put in /etc/dpkg/dpkg.cfg) to the explicit command dpkg --add-architecture that only needs to be called once (see mail here). As of today (December 2th), the promised email for the other interface changes is still not here.

On November 23th, I reviewed Guillem’s work and tried to run the code in his branch. I spent the whole day chasing up regressions and submitted lots of fixes to Guillem. Thanks to the extensive test-suite I wrote when I developed my branch, it has been fairly easy to track them all down.

All the issues I reported have been fixed in the latest version of Guillem’s branch although the fixes are often slightly different from those that I submitted.

Dpkg: Squeeze Backport

At the start of the month, I uploaded what I expected to be a fairly uncontroversial backport of dpkg It turns out I was wrong.

After some discussion, I think we came to an agreement that it was acceptable to backport dpkg-dev and libdpkg-perl only. My goal was not to bring the latest dpkg to users but to make it easier for package maintainers to backport packages using new features provided by dpkg-dev >= 1.16 (such as hardening build flags, the makefile snippets provided in /usr/share/dpkg/, or the improved dpkg-buildflags interface).

Thus I modified the source package uploaded to squeeze-backports to build only dpkg-dev and libdpkg-perl. It has been uploaded on November 23th and it’s waiting in the NEW queue for a backports admin to process it.

Misc Dpkg Work

I merged a patch of Colin Watson to be able to verify build-dependencies for a foreign architecture (taking into account the Multi-Arch status of each package listed).

I released dpkg with two minor fixes that were sitting in the sid branch. I wanted to get rid of this so that the path is clear for a 1.16.2 upload with multiarch. The package just migrated to testing so we’re fine.

I spent another day doing dpkg bug triaging on Launchpad, we’re now down to 77 bugs with many of them tagged as incomplete and likely to expire in 2 months.

The Debian Administrator’s Handbook

eBookWe released a sample chapter so that it’s easier to have an idea of the quality of the book. The chapter covers the APT tools quite extensively. I bet that even you could learn something about apt-get/aptitude…

The crowfunding campaign on Ulule ended on November 28th.
With 673 supporters, we raised 24345 EUR. Of those, 14935 EUR have been put in the liberation fund and the rest corresponds to the various pre-orders and rewards offered.

This means that the translation will happen (we just started) but that the book is currently not going to be released under a free license. Don’t despair… As planned, the liberation campaign is carried on until the 25 K€ target is reached!

Instead of being hosted on Ulule, this permanent campaign is on the project website at debian-handbook.info/liberation/. Note that any contribution of 10 EUR or more means that you get a copy of the ebook as soon as it’s available (even if the liberation target is not reached).

Package Tracking System

At the start of the month, I filed two ideas of improvements for the PTS in the bug tracking system: #647258 is about showing outstanding bugs that relate to a release goal and #647901 is about warning maintainers that the package is affected by a current transition. If you’re a coder and want to start contributing to Debian and its QA team, those bugs could be interesting targets for a start. 🙂 In both cases, I have been in contact with members of the release team because those ideas require some structured data from the release team as input. Thanks to Meddi Dohguy and Niels Thykier for their help.

Later in the month, the topic of relocating the PTS once again came up. For historical reasons, the PTS was hosted on master.debian.org together with the BTS. Nowadays the BTS has its own host and it made no sense anymore to have the PTS separate from the rest of the QA services hosted on qa.debian.org (currently quantz.debian.org). So together with Martin Zobel Helas we took care to plan the migration and on November 19th we executed the plan. It worked like a charm and almost nobody noticed (only one undocumented dependency was missed, which broke the SOAP interface).

Misc Packaging Work

WordPress was broken in Ubuntu and it was also not properly synchronized with Debian due to an almost useless change on their side. Thus I requested a sync so that the working version from Debian gets imported in Ubuntu.

I sponsored the docbook-xsl 1.76.1 upload that I needed for Publican. Then I updated Publican just to discover that the test-suite triggers a new bug in fop (filed as #649476). I disabled the test-suite temporarily and uploaded Publican 2.8 to unstable. BTW, I also filed 2 upstream bugs with patches for issues I discovered while trying to generate the sample chapter of my book (see here and here).

I uploaded a version 0.7.1 of nautilus-dropbox and fixed #648215 at the same time. I made an NMU of bison to fix a long-standing release critical bug that hit me once more during an upgrade (see #645038).

I uploaded to experimental a new version of gnome-shell-timer compatible with GNOME 3.2. I took the opportunity to install from experimental the few GNOME 3.2 packages which are not yet in unstable…


See you next month for a new summary of my activities.