Blog entries

  • Apycot for Mercurial

    2010/02/11 by Pierre-Yves David

    What is apycot

    apycot is a highly extensible test automatization tool used for Continuous Integration. It can:

    • download the project from a version controlled repository (like SVN or Hg);
    • install it from scratch with all dependencies;
    • run various checkers;
    • store the results in a CubicWeb database;
    • post-process the results;
    • display the results in various format (html, xml, pdf, mail, RSS...);
    • repeat the whole procedure with various configurations;
    • get triggered by new changesets or run periodically.

    For an example, take a look at the "test reports" tab of the logilab-common project.

    Setting up an apycot for Mercurial

    During the mercurial sprint, we set up a proof-of-concept environment running six different checkers:

    • Check syntax of all python files.
    • Check syntax of all documentation files.
    • Run pylint on the mercurial source code with the mercurial pylintrc.
    • Run the script included in mercurial checking style and python errors
    • Run the Mercurial's test suite.
    • Run Mercurial's benchmark on a reference repository.

    The first three checkers, shipped with apycot, were set up quickly. The last three are mercurial specific and required few additional tweaks to be integrated to apycot.

    The bot was setup to run with all public mercurial repositories. Five checkers immediately proved useful as they pointed out some errors or warnings (on some rarely used contrib files it even found a syntax error).


    A public instance is being set up. It will provide features that the community is looking forward to:

    • testing all python versions;
    • running pure python or the C variant;
    • code coverage of the test suite;
    • performance history.


    apycot proved to be highly flexible and could quickly be adapted to Mercurial's test suite even for people new to apycot. The advantages of continuously running different long running tests is obvious. So apycot seems to be a very valuable tool for improving the software development process.

  • Mercurial 2.3 sprint, Day 1-2-3

    2012/05/15 by Pierre-Yves David

    I'm now back from Copenhagen were I attended the mercurial 2.3 sprint with twenty other people. A huge amount of work was done in a very friendly atmosphere.

    Regarding mercurial's core:

    • Bookmark behaviour was improved to get closer to named branch's behaviour.
    • Several performance improvements regarding branches and heads caches. The heads cache refactoring improves rebase performance on huge repository (thanks to Facebook and Atlassian).
    • The concept I'm working on, Obsolete markers, was a highly discussed subject and is expected to get partly into the core in the near future. Thanks to my employer Logilab for paying me to work on this topic.
    • General code cleanup and lock validation.

    Regarding the bundled extension :

    • Some fixes where made to progress which is now closer to getting into mercurial's core.
    • Histedit and keyring extensions are scheduled to be shipped with mercurial.
    • Some old and unmaintained extensions (children, hgtk) are now deprecated.
    • The LargeFile extension got some new features (thanks to the folks from Unity3D)
    • Rebase will use the --detach flag by default in the next release.

    Regarding the project itself:

    Regarding other extensions:

    And I'm probably forgetting some stuff. Special thanks to Unity3D for hosting the sprint and providing power, network and food during these 3 days.

  • Retour OSDC 2012 - présentation mercurial DVCS

    2012/12/05 by Pierre-Yves David

    À la mi-octobre, j'ai participé à la conférence OSDC 2012 à Paris. Le but de cette conférence est de permettre à des développeurs de différentes communautés de se rencontrer dans une ambiance chaleureuse. De fait, j'ai découvert un certain nombre de projets et de pratiques intéressants.

    Le samedi, j'ai découvert des outils javascript mettant l'accent sur les modèles de données comme AngularJS ou BackBone, Une présentation rapide du langage Go, le très prometteur portage des outils GCC sur Windows nommé MinGW ainsi que les nouveautés de GCC 4.8. La journée s'est conclut sur des présentations éclairs dont je retiendrai surtout la perversité des opérateurs secrets en Perl et le livre Javascript Éloquent intégralement en HTML qui en profite donc pour inclure exemples et exercices interactifs au fil du contenu.

    Le dimanche matin j'ai ouvert le bal en présentant mes travaux actuels dans le DVCS Mercurial: l'Évolution de Changeset (PDF de la présentation). Ce concept permet aux développeurs de découvrir la réécriture d'historique de manière simple et sûre. Les utilisateurs avancés ont accès de leur côté à des processus de travail et de revue encore inédits dans le monde des DVCS. Ma présentation fut suivie d'une introduction à la découverte automatique de bugs grâce à la bisection dans les DVCS.

    Changesets Evolution : Mercurial secoue le monde du dvcs par Pierre-Yves David

    La journée s'est poursuivie avec une présentation du langage Haskell, de la bibliothèque de visualisation sigmajs et la spécification SPORE apportant un peu d'espoir dans les spécifications de services Web REST.

  • Febuary 2013: Mercurial channel "tour"

    2013/01/22 by Pierre-Yves David

    The Release candidate version of Mercurial 2.5 was released last sunday.

    This new version makes a major change in the way "hidden" changesets are handled. In 2.4 only hg log (and a few others) would support effectively hiding "hidden" changesets. Now all hg commands are transparently compatible with the hidden revision concept. This is a considerable step towards changeset evolution, the next-generation collaboration technology that I'm developing for Mercurial.

    The 2.5 cycle is almost over, but there is no time to rest yet, Saturday the 2th of February, I will give a talk about changeset evolution concept at FOSDEM in the Mozilla Room. This talk in an updated version of the one I gave at 2012 (video in french).

    The week after, I'm crossing the channel to attend the Mercurial 2.6 Sprint hosted by Facebook London. I expect a lot of discussion about the user interface and network access of changeset evolution.

    The HG 2.3 sprint