Mini Debconf & merchandising

November 17th, 2012

Next week end, November 24th and 25th, the mini Debconf will take place at EPITA in Paris.

Mehdi Dogguy and I worked hard on the organization and on building a great program for this 2012 conference. This mini debconf will cover many subjects like Gnome (both as upstream and downstream), the Release team, how the Linux is packaged in Debian, etc.
The keynote will be "Free software and Debian, 20 years after" by Roberto Di Cosmo.

Also, some merchandising will be proposed during the event by the association Debian France. Here is a quick list:

long-sleeved polo
Long-sleeved polo

40 euros - 10 pieces

Sleeveless polo
Sleeveless polo

25 euros - 100 pieces

Thanks to Tanguy Ortolo for taking take of the order.

Buff Debian
Buff Debian

18 euros - 75 pieces.

It is described as Original Multifunctional Headwear. Real life example in video.
I love them!

Finally, we will sell two kinds of Debian branded Sticker Portable:
Sticker Debian
Sticker Debian

1 euro - 100 pieces.

They can be also ordered on the it2l website. Thanks to Jérôme Lemaire for providing these great products.

If these products are successful, we will probably produce more for FOSDEM!

For more information about the conference:
The official website
Wiki page for subscription

libc++: New C++ standard library in Debian

Août 15th, 2012

Thanks to the work of Andrej Belym, Debian has now a new C++ standard library. This work has been done in the context of the Google Summer of Code 2012.
Available in Debian Experimental, this new packages provides both the runtime libraries (libc++abi1) and the C++ headers (libc++-dev).

With this library, it is possible to build a C++-based program without any dependency on libstdc++.

For example, as detailed in README.Debian, with the (amazing) C++ code:

// foo.cpp
#include <iostream>

int main() {
std::cout < < "plop" << std ::endl;
return 0;

with clang++ (or g++) will give:

$ clang++ -o plop foo.cpp
$ ldd plop |grep c++ => /usr/lib/x86_64-linux-gnu/ (0x00007f15791cb000)

Using libc++, it will drop the dependency on libstdc++ to use lib++

$ clang++ -stdlib=libc++ -o plop foo.cpp
$ ldd plop |grep c++ => /usr/lib/x86_64-linux-gnu/ (0x00007f87464df000)

For the record, it is not that trivial to do with g++. The command being:

g++ -nostdlib -lc++ -lc++abi -std=c++11 -o plop /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o foo.cpp /usr/lib/x86_64-linux-gnu/crtn.o -isystem/usr/include/c++/v1 -lc -lgcc_s

Besides this change, libc++ provides a support of C++ 11, considered as "correct" against the C++11 standard by upstream.

// bar.cpp
#include <chrono>
int main() {
return 0;

clang++ -stdlib=libc++ -o bar bar.cpp

More information:

News on Debian & clang

Juillet 24th, 2012

A couple week ago, during the last debconf (Debian Conference) in Managua/Nicaragua, I presented the latest developments about the inclusion of clang in the Debian architecture.

To sum up (details are available in the slides and the video), the rebuild of the Debian archive with Clang 3.1 increased the number of failures from 8.8 to 12.1%. The main reason is that further checks have been added to clang.

With Paul Tagliamonte as co-mentor and Alexander Pashaliyski as a GSoC student, we made great progress in bringing Clang as A new compiler in the Debian infrastructure.

The various feedbacks that I had during Debconf were pretty good. It interests many people for reasons like Quality Assurance (more checks), performances, hackability or to decorrelate Debian and GCC.

Build Debian with another compiler - Slides
Build Debian with another compiler - Video

A nice resume of my talk has been made by Michael Larabel on Phoronix:
Decoupling GCC From Debian By Using LLVM/Clang

Who is in control of LLVM/Clang ?

Juillet 22nd, 2012

During my various chats and presentations on LLVM/Clang, one of the common criticism on LLVM/Clang is about the Apple's (supposed?) control on the platform.

Even if I am not concerned by this concern, here are some statistics about the development. Basically, I used the git history to build a list of all the author. If domain names were clear (ex:,, etc), I used them for the paternity of the commit. If there were not clear (ex:,, I dig on the web to find the employer (Linkedin was my friend).

Of course, identifying individuals are pretty tough. Their percentages can be considered as a minimal figure.

Full history

10 000 commits (about a year)
3 000 commits (~a month)

To sum up, we can easily see that the percentage of contributions of Apple is decreasing over the time.
However, we all know that the number of commits is not the best metric to measure the control of one on a project.

Source: Processed data (please contact me in case of mistake)

Interview in FLOSS for Science

Juillet 20th, 2012

A couple weeks ago, I have been interviewed by the news site "Free Libre open source software for science and engineering" about Scilab and my work in Scilab Enterprises.
I am happy to share it: