Mercurial Conference Paris 2022

The conference is postponed to 2023

Read the blog post announcing the Mercurial Paris Conference 2022 is postponed to 2023 here. This page is now outdated.

September 21-23, 2022 in Paris

The event will take place from the Wednesday 21th of September 9:00 am to the Friday 23th of September 5:00pm in Paris, Sorbonne University.



September, Wednesday 21th from 9:00am to 6:00pm

Location: Logilab, 104 Bd Auguste Blanqui, 75013 Paris

Mercurial usage and workflow

A unique occasion to get acquainted and up to date with the most modern ways of using Mercurial, including history rewriting with Evolve and topics. We will cover the basic setup and the fundamentals before jumping to more advanced subjects.

  • 09:00-12:00
  • Raphaël Gomès
  • Company: Octobus

Heptapod: Using Mercurial with the GitLab DevOps platform

Heptapod adds Mercurial support to the GitLab DevOps platform to provide issues, merge requests, CI/CD and more to Mercurial users. Heptapod has notably particular built-in support for Evolve and topics. This workshop will put in practice the 'Mercurial usage and workflow' workshop by setting up concrete team development scenarios using a Heptapod server. Participants will be encouraged to assume different roles ranging from simple contributor up to maintainer.


September, Thursday 22th from 9:00am to 6:00pm

Location: Irill, Sorbonne University, 4 place Jussieu, Paris, France

Stability and innovation

Mercurial and Logilab

Mercurial has been the tool-of-choice picked by Logilab folks since a long time. Why this choice? How is it used at Logilab? What about Logilab upstream contributions? Nicolas Chauvat will present the Mercurial history at Logilab and answer all those questions.

  • 10:00
  • Speaker name: Nicolas Chauvat
  • Company: Logilab

Using Mercurial, evolve and hg-git in an academic context

I am a CNRS researcher working on instabilities and turbulence in fluids. In our group, we base a lot of our work on few Python packages. The development of these packages involves people with very different levels of experience in coding and in versioning. Depending on the software project, the development is hosted on different platforms:, a university Gitlab instance and Github. For the projects hosted on Heptapod, we use a workflow based on Merge Requests (MR), topics and the evolve extension. This workflow presents great advantages for us:

  • the code review associated with each MR is very efficient to improve the skills and productivity of the students.
  • Topics and evolve allow the experienced developers to directly interact on the MR and on their history (in particular with rebase, amend, fold, absorb, ...). The readability of the history of the repositories is largely improved.
  • Fairly quickly, students master at least amend, lose the apprehension of making bad commits and tend to commit small changesets and to push more often. With hg-git, Mercurial can also be used for projects hosted on Gitlab and Github so students do not need to directly interact with Git.

  • 10:20

  • Speaker name: Pierre Augier
  • Company: CNRS, UGA, LEGI

Mercurial usage at XCG Consulting

Mercurial and its extensions, including the heavy use of evolve and confman. The move from to the Heptapod instance and the changes in our CI tool from to GitLab's own CI. The better integration of topic/evolve that smoothed our workflow. Deployment and our contribution to Vendir, a tool that manages directory’s contents, to add support for Mercurial.

XEmacs and Mercurial: fifteen years of good experiences

  • 11:20
  • Speaker name: Aidan Kehoe
  • Project: Xemacs


Heptapod, three years of Mercurial in GitLab and growing

In this talk, we will describe the state and near future of Heptapod and its hosted offerings.

Lots happened since Heptapod was first presented three years ago at the Mercurial Paris conference. We have kept on bringing the power of GitLab to Mercurial users since then. Thanks to our partnership with Clever Cloud, we have launched a public hosting offering ( and its counterpart for Free and Open Source Software ( has become the development platform of several important projects, among which now figures the Mercurial core project itself, one of the latest additions. We will survey the current capabilities of Heptapod and share perspectives for the upcoming year.

Lairucrem presentation

Lairucrem provides a useful user interface to the Mercurial DVCS. It is a text-based interactive interface that helps developers on their daily usage of Mercurial.

  • 12:00
  • Speaker name: Alain Leufroy
  • Company: Pythonian

Mercurial at Scale

How Mercurial is used to develop Tryton

Tryton is a business application with about 200 modules which are developed as distinct packages. We will show how we integrated mercurial with our bugtracker, codereview and continuous integration systems with such amount of repositories. And finally why we choose to migrate to Heptapod.

  • 14:30
  • Speaker name: Cédric Krier
  • Project: Tryton

Mercurial usage at Nokia: scaling up to multi-gigabyte repositories with hundreds of developers for fun and games

We will give an overview of Mercurial usage at Nokia, showing the architecture of our Mercurial setup and some statistics of our use. Additionally, we will focus on what optimizations we did and specific Mercurial features we used to enhance scalability.

Specific topics that will be mentioned: (streaming) clonebundles, pullbundles, mercurial-server, mirroring.

Mercurial usage at Google

Hear about how we use Mercurial as a client for our internal non-Mercurial monorepo.

  • 15:30
  • Speaker name: Martin von Zweigbergk
  • Company: Google
  • Note: remote video talk

Development Update

Mercurial Performance / Rust

  • 16:10
  • Speaker name: Raphaël Gomès
  • Company: Octobus

One of the stated goals of Mercurial has always been to provide a fast user experience, and aspects of that goal are out of reach for a command-line tool written in Python. We will go through the different ways and reasons we're using Rust in Mercurial and how it can improve the user/server experience.

State of changeset evolution

  • 16:30
  • Speaker name: Pierre-Yves David
  • Company: Octobus

Mercurial has safe and strong history rewriting capabilities thanks to the changeset Evolution concept. It allows users an unprecedented level of collaboration on drafts through their DVCS. In this presentation, we will go over the core principles of this unique feature and give you an update on its implementation status in Mercurial.


September, Friday 23th from 9:00am to 6:00pm

Location: Irill, Sorbonne University, 4 place Jussieu, Paris, France

Organizer contact




UPMC - IRILL Tour 16, Couloir 15-16, 1er étage 4 place Jussieu 75252 Paris Cedex 05


104 Boulevard Auguste Blanqui 75013 Paris


IRILL - Research and Innovation on Free Software

The mission of IRILL, the Center for Research and Innovation on Free Software, is to bring together in one place leading researchers and scientists, expert FOSS developers, and FOSS industry players to tackle the three fundamental challenges that FOSS poses today:

  • Scientific: study, explore and solve the new problems raised by the development, maintenance and wildly varying evolution process of the large mass of code that FOSS gives access to.
  • Educational: adapt curricula for users, system administrators, and developers to prepare them for a computing infrastructure in which FOSS plays a prime role.
  • Ecomomic: contribute to create a sustainable ecosystem for the FOSS innovations.

IRILL's mission is to foster exchange of knowledge between FOSS developer communities and computer science researchers: new problems coming from the FOSS world will feed the work of researchers who are eager not only to find innovative solutions, but also to turn these solutions into tools that will improve the real-world, daily work of the FOSS communities. Developers and researchers will bring in their joint expertise to create new course materials for computing courses.

Learn more: