FOSDEM is one of the largest gatherings of Free Software contributors in the world and happens each February in Brussels (Belgium). One of the developer rooms will be the CrossDesktop DevRoom, which will host Desktop-related talks.

We are now inviting proposals for talks about Free/Libre/Open-source Software on the topics of Desktop development, Desktop applications and interoperativity amongst Desktop Environments. This is a unique opportunity to show novel ideas and developments to a wide technical audience.

Topics accepted include, but are not limited to: Enlightenment, Gnome, KDE, XFCE, Windows, Mac OS X, general desktop matters, applications that enhance desktops and web (when related to desktop).

Talks can be very specific, such as developing mobile applications with Qt Quick; or as general as predictions for the fusion of Desktop and web in 5 years time. Topics that are of interest to the users and developers of all desktop environments are especially welcome. The FOSDEM 2011 schedule might give you some inspiration.

Please include the following information when submitting a proposal: your name, the title of your talk (please be descriptive, as titles will be listed with around 250 from other projects) and a short abstract of one or two paragraphs.

The deadline for submissions is December 20th 2011. FOSDEM will be held on the weekend of 4-5 February 2012. Please submit your proposals to

Also, if you are attending FOSDEM 2012, please add yourself to the KDE community wiki page so that we organize better. We need volunteers for the booth!


Red Hat‘s Matthew Garrett let the cat out of the bag about a month ago: when UEFI Secure Boot is adopted by mainboard manufacturers to satisfy Microsoft Windows 8 requirements, it may very well be the case that Linux and others (BSD, Haiku, Minix, OS/2, etc) will no longer boot.

Matthew has written about it extensively and seems to know very well what the issues are (part I, part II), the details about signing binaries and why Linux does not support Secure Boot yet.

The Free Software Foundation has also released a statement and started a campaign, which is, as usually, anti-Microsoft instead of pro-solutions.

Now let me express my opinion on this matter: this is not Microsoft’s fault.


Let’s see what are the facts in this controversy:

  • Secure Boot is here to stay. In my humble opinion, the idea is good and it will prevent and/or lessen malware effects, especially on Windows.
  • Binaries need to be signed with a certificate from the binaries’ vendor (Microsoft, Apple, Red Hat, etc)
  • The certificate that signs those binaries needs to be installed in the UEFI BIOS
  • Everybody wants their certificate bundled with the UEFI BIOS so that their operating system works “out of the box”
  • Given that there are many UEFI and mainboard manufacturers, getting your certificate included is not an easy task: it requires time, effort and money.


The problem stems from the fact that most Linux vendors do not have the power to get their certificates in UEFI BIOS. Red Hat and Suse will for sure get their certificates bundled in server UEFI BIOS. Debian and Ubuntu? Maybe. NetBSD, OpenIndiana, Slackware, etc? No way.

This is, in my humble opinion, a serious defect in the standard. A huge omission. Apparently while developing the Secure Boot specification everybody was busy talking about signed binaries, yet nobody thought for a second how the certificates will get into the UEFI BIOS.

What should have been done

The UEFI secure boot standard should have defined an organization (a “Secure Boot Certification Authority”) that would issue and/or receive certificates from organizations/companies (Red Hat, Oracle, Ubuntu, Microsoft, Apple, etc) that want their binaries signed.

This SBCA would also be in charge of verifying the background of those organizations.

There is actually no need for a new organization: just use an existing one, such as Verisign, that carries on with this task for Microsoft for kernel-level binaries (AuthentiCode).

Given that there is no Secure Boot Certification Authority, Microsoft asked BIOS (UEFI) developers and manufacturers to include their certificates, which looks 100% logical to me. The fact that Linux distributions do not have such power is unfortunate, but it is not Microsoft’s fault at all.

What can we do?

Given its strong ties with Intel, AMD and others, maybe the Linux Foundation could start a task force and a “Temporary Secure Boot Certification Authority” to deal with UEFI BIOS manufacturers and developers.

This task force and TSBCA would act as a proxy for minorities such as Linux, BSD, etc distributions.

I am convinced this is our best chance to get something done in a reasonable amount of time.

Complaining will not get us anything. Screaming at Microsoft will not get us anything. We need to propose solutions.

Wait! Non-Microsoft certificates? Why?

In addition to the missing Secure Boot Certification Authority, there is a second problem apparently nobody is talking about: what is the advantage mainboard manufacturers get from including non-Microsoft certificates?

For instance: why would Gigabyte (or any other mainboard manufacturer) include the certificate for, say, Haiku?

The benefit for Gigabyte would be negligible and if someone with ill-intentions gets Haiku’s certificate, that piece of malware will be installable on all Gigabyte’s mainboards.This would lead to manufacturer-targetted malware, which would be fatal to Gigabyte: “oh, want to be immune to the-grandchild-of-Stuxnet? Buy (a computer with) an MSI mainboard, which does not include Haiku’s certificate”

Given that 99% of desktops and laptops only run Windows, the result of this (yet unresolved) problem would be that manufacturers will only install Microsoft certificates, therefore they would be immune to malware signed with a Slackware certificate in the wild.

If we are lucky, mainboard manufacturers will give us an utility to install more certificates under your own risk.

The solution to the first problem looks easy to me. The solution to the second looks much more worrying to me.


A while ago I said Koen from Emweb made an interesting proposal at FOSDEM about emerge, the KDE Windows build tool.

Yesterday, Jarosław Staniek and I reaffirmed our commitment to ’emerge’. Today, I’d like to go a bit further: let’s bring more developers to emerge by opening it up to other projects. Keep reading!

What is emerge, why is it important and what was Koen’s proposal?

Fact: Microsoft Windows is very different to Unix in regards to development.

On Unix platforms -that includes Linux and Mac OS X-, software is usually installed to /usr: applications in /usr/bin and /usr/sbin, libraries in /usr/lib, headers in /usr/include, common resources in /usr/share, etc. Also, dependency management is usually something you can count on: when you install kdelibs5-dev in Ubuntu, it will automatically install libqt4-dev, kdelibs5-data, libfreetype (runtime), etc That makes setting up a development environment a very easy task: look for shared libraries, header files, etc in the common places and you will probably find them.

On Windows there is nothing like that. When you want to compile an application, you need to provide (build and install) all its dependencies, and you need to tell Visual Studio where to find everything. Even CMake usually needs some help in the form of a hint for CMAKE_PREFIX_PATH. As you may imagine, building KDE, which has more than 200 third party dependencies and tens of modules (and with the move + split to git, many more) becomes an almost insurmountable task.

‘Emerge’ to the rescue: inspired by Gentoo‘s emerge, Ralf Habacker, Christian Ehrlicher, Patrick Spendrin and others (yours faithfully included) developed a tool which downloads the source, configures, builds, installs and packages KDE and its dependencies. It makes a world of difference when building KDE. Actually, it makes building KDE on Windows possible. Once more: thank you very much guys, impressive tool.

There are two well-differentiated parts in emerge, the ‘engine’ and the ‘recipes’.

Read More →

I have been packaging for Debian for a few years now. My first “serious” package was Wt back in 2007, but I had been backporting for Ubuntu for at least 2 years already, which means I have been doing .deb packaging for about 5 years (!).

Last week I decided it was about time stop nagging my sponsors (Vincent Bernat, Thomas Girard and Sune Vuorela) every time I wanted to update the packages I maintain (witty, ace and libmsn), and I finally started the Debian New Maintainer process.

The main reason I had not applied for Debian Maintainer yet was it requires some bureaucracy and, well, I’d rather spend my time coding or packaging than doing paperwork 🙂

I sent my Declaration of Intent and soon after, Thomas and Vincent replied and supported my application with very very nice and kind words. Thank you, guys! I’m flattered! 🙄

Had I known I would be buttered up so much, I would have certainly applied a long time ago! 😀

But you know what is the best part of this? It shows how open source projects take advantage of all the tools and communications channels we have (IRC, mailing lists, sprints, conferences, etc), and make distributed development work very well: here we have a 900-developers project in which two French guys are praising an Spanish guy they have never, ever met face-to-face (only e-mail, occasional IRC, and the most important of all: code review). Meritocracy at its full extent. Have you ever seen that in a traditional 100,000 workers company with hundreds of developers working in a single project?

Do not waste my hard disk!

I recently acquired an 2 TB hard disk drive, which I immediately formatted with ext4. Given that mkfs.ext4 defaults to 5% reserved blocks for too, that amounts to 100 GB of lost* space.

Wow. 100 GB. On a desktop machine. For root.

While mkfs belongs to e2fsprogs, I think this requires action on the distributions side. Let me explain.

If you are installing a server, 5% makes perfect sense: there are a lot of logfiles, updates, potential break-ins and other disasters-to-happen for which root-reserved space will be preciously required. 5% is a good choice here. If 5% is too much (or too little), it will not matter: any decent sysadmin knows mkfs.ext4 -m and tune2fs -m (if you don’t, Martin will teach you).

On the other hand, if you are installing Ubuntu on your laptop, you probably don’t know shit about mkfs, tune2fs, 5%, etc. You only know by removing Windows and installing Linux you’ve magically lost 100GB of space. Vanished.

So here is my request to Linux distributions: when installing a distribution in “desktop profile” (i. e. not Debian in “server” profile, RHEL, SLES, Ubuntu Server, etc), DO NOT RESERVE 5% to root. 100 or 200 MEGABYTES should be more than enough.

* Yes, I know it’s not really “lost” but just “unusable by normal users” but that technicality doesn’t matter to 99% of the people out there.

Ubuntu Jaunty reached end of support life last October and apparently packages have been removed from Launchpad PPAs too.

Given that it is impossible for me to build binary packages for Jaunty in the Wt PPA due to missing packages, the Wt PPA will no longer provide new packages for Ubuntu Jaunty. The last stable version of Wt for Jaunty is 3.1.6.

On April 2011, Karmic reaches end of support, and Hardy reaches end of support for desktop (support for servers will be available until April 2013). I will provide Wt packages for those distributions while Launchpad supports them.

Packages for 3.1.7a are already available for Ubuntu Maverick, Lucid and Karmic, as usual. Packages for Debian Lenny (in the Wt OBS repository) and Ubuntu Hardy packages will be ready in a few hours. Source packages for Debian Sid are available from mentors.

Wt (pronounced ‘witty’) is a C++ library and application server for developing and deploying web applications. The API is widget-centric and offers complete abstraction of any web-specific application details. You could say it’s like Qt but for the web.

I have been packaging Wt for Debian and Ubuntu, and providing backports for Ubuntu, for years now.

So far, Wt packages were just one more citizen amongst the many other packages in my PPA. Invariably, I received complaints and suggestions pointing in the direction of chaos and havoc: installing Wt from my PPA and running apt-get full-upgrade meant many packages were updated (just try and do that on a Hardy: half the distribution is upgraded :-)). Some of the updated packages were as essential as g++, Boost, Qt, Samba, ALSA and GStreamer. While I seldomly broke anything, I understand people would be worried for their systems, especially people running servers.

From today on, Wt packages will no longer be available from my PPA but from a new, dedicated repository: the Wt PPA.

The Wt PPA contains only the essential packages required to install Wt on a basic system. You do not need to enable backports, proposed or anything: just add the Wt PPA repository to your out-of-the-box Ubuntu and install the libwt* packages. Currently, packages for Hardy, Jaunty, Karmic and Lucid are available. Packages for Maverick will be available as soon as bug 647597 is fixed.

Click here to go to the Wt PPA

I hope you enjoy it.

PS If you need packages for Debian Lenny, check my OpenSuse Build Service repository. Read more at the Wt wiki

Today I received an e-mail from Vincent about some strange warnings dpkg-shlibdeps was showing when building from source the Wt packages on Debian:

dpkg-shlibdeps: warning: symbol pthread_join used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_key_delete used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_init used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_setspecific used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_settype used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_detach used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_destroy used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_getspecific used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_key_create used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_sigmask used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_settype used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_init used by debian/witty/usr/lib/ found in none of the libraries.
dpkg-shlibdeps: warning: symbol pthread_mutexattr_destroy used by debian/witty/usr/lib/ found in none of the libraries.

He asked if I knew what was that (a dpkg-shlibdeps bug?) and what did it mean, it case it was correct.

That error means pthread_join, pthread_mutexattr_destroy, etc are used by and but those libraries are not linked to by Wt’s buildsystem. I. e. the linker command line when putting and together does not have a “-lpthread“.

Is dpkg-shlibdeps right about that? Yes, it is:

  • uses in the XML library (Wt bundles the sources ot MiniXML and compiles them as part of
  • uses in WServer.C

So, if the buildsystem is not linking and to, why doesn’t linking fail with “unresolved reference” errors? It’s because of the link interface in Boost is wrong.

Link interface? What’s that?

If you are reading me via Planet KDE, you probably know what I’m talking about because Alex has written about this. If you don’t know what I’m talking about, keep reading.

Say you have, and

  • does not link to any external library, save for glibc
  • links only to and glibc
  • links only and glibc

When you run ldd, what will you get? This?

$ ldd => (0xb7f66000) => /usr/lib/ => /lib/tls/i686/cmov/
/lib/ (0xb7f67000)

or this?

$ ldd => (0xb7f66000) => /usr/lib/ => /usr/lib/ < ======= => /lib/tls/i686/cmov/
/lib/ (0xb7f67000)

The answer is you’ll see the second output: is linking to, although when you linked it you only did gcc -o libC.c -lB (no -lA, so no explicit linking to

libC -> libB -> libA

Why is that? Why is being dragged to It’s because of what we call “link interface”

As links to, by default,‘s ELF header will have every library links to as NEEDED:‘s dependencies have been transitively passed into! Usually that’s not what you want, therefore it is possible to specify a “reduced link interface”: given that is only used internally in (users of do not need to use any type or function defined in libA), there is no need to link to


  • As and link to from Boost
  • In Debian, Boost is compiled with threads (i. e. it links to
  • Boost does not publish a reduced link interface but the full link interface (i. e. every dependency of Boost is transitively passed into applications/libraries using Boost)

… even though and were not linking to explicitly, they were picking from and no linkage error happened. If would not export (it should not!), linkage of and would have failed and the authors of Wt would have noticed the bug in their build system.

While this is not a critical issue, it makes your application/library load slower, because it needs to resolve and load the NEEDED libraries.

Please note this discussion is valid for any operating system, including Windows and Mac OS X.

If you use CMake as your build system and you want to adopt a reduced link interface, take a look at the CMake docs for TARGET_LINK_LIBRARIES, particularly the LINK_INTERFACE_LIBRARIES section:

Library dependencies are transitive by default. When this target is linked into another target then the libraries linked to this target will appear on the link line for the other target too. See the LINK_INTERFACE_LIBRARIES target property to override the set of transitive link dependencies for a target.

target_link_libraries( LINK_INTERFACE_LIBRARIES
[[debug|optimized|general] ] …)

The LINK_INTERFACE_LIBRARIES mode appends the libraries to the LINK_INTERFACE_LIBRARIES and its per-configuration equivalent target properties instead of using them for linking. Libraries specified as “debug” are appended to the the LINK_INTERFACE_LIBRARIES_DEBUG property (or to the properties corresponding to configurations listed in the DEBUG_CONFIGURATIONS global property if it is set). Libraries specified as “optimized” are appended to the the LINK_INTERFACE_LIBRARIES property. Libraries specified as “general” (or without any keyword) are treated as if specified for both “debug” and “optimized”.

NB: The comments in this blog do not work due to a hosting issue

Are you a developer and use ACE, TAO, CIAO? Do you use and/or deploy to Debian, Ubuntu or any other Debian-based distribution?

If you answered affirmatively to those two questions, you have probably noticed Debian still ships ACE 5.6.3, which is 18 months old. The reason is twofold:

  • ACE is a complex beast. The source tarball generates 59 binary packages for 5.6.3, and that’s only to increase in the latest version (5.7.4).
  • The only Debian developer working on ACE, Thomas Girard, is too busy at the moment. He did a great job maintaing ACE for years but now it’s time for others to help him.

Therefore, if you use ACE and Debian directly or indirectly, please step in and help me get the latest ACE in Debian. I’m half done but I’m having trouble with autotools (the autotools build system in ACE seems to need some love, I’m probably moving to the traditional build system) and I do not know where to put some of the new libraries (DAnCE, etc).

NB: The comments in this blog do not work due to a hosting issue, please contact me directly by e-mail: or subscribe to the pkg-ace-devel mailing list.

A couple of weeks ago, I said I would not be backporting the latest versions of Glib2, Gtk+, GStreamer, etc to Hardy.

Today I decided I needed a newer GStreamer on my Hardy machine (where I build and use KDE from trunk almost daily) because I wanted to use libQtGstreamer.

As I expected, this requires major surgery to Hardy. Two prominent components of Hardy, ffmpeg and PulseAudio, require relatively recent versions. I don’t even know if it’s possible to build them due to limitations in Hardy’s kernel V4L2 support. In addition to that, I’m leaving on holidays to London and I won’t be able to work on this until next Wednesday.

Summary: IF YOU USE MY PPA AT THIS MOMENT, IT WILL BREAK YOUR HARDY INSTALLATION! BE VERY CAREFUL IF YOU RUN APTITUDE FULL-UPGRADE! I don’t like having the PPA broken for so long but I have to wake up in 4 hours and I really need to get some sleep.