When and where

  • Sprint Americas

    • When: Friday 9 March
    • Where: Argentina, Cordoba (FaMAF, Universidad Nacional de Córdoba)
  • Sprint Europe

    • When: Friday 30 March - Sunday 1 April

    • Where: UK, Southampton (University ECS department, building 59 (The ‘Zepler Building’) ground floor, seminar room 1)

      • directions to ECS

      • public transit “Unilink” routemap

      • Unilink bus times ~ The “Highfield interchange” stop is on campus, very close to the Zepler building - on the ECS map above, it’s sort-of in the space between buildings [6,4,67] just above the confusingly labeled “Winchester Campus” on this map

      • If arriving by train, you’ll want to catch the U1A bus, from outside the platform 4 side of Central Train Station. A “day return” ticket is £3 and gives you unlimited travel on the buses, so is probably best.

      • we’ve booked a 7 person house (4 bedrooms) and we still have room for 4 people



  • Guillaume Hoffmann
  • Mathias Etcheverry
  • Miguel Pagano


  • Eric Kow [Westgate] - infrastructure, look at GSoC 2011
  • Owen Stephens - conflictors
  • Florent Becker [Westgate] - 2.8
  • BSRK Aditya [Westgate] -
  • Ganesh Sittampalam [Westgate] - 2.8, rebase


Starter tasks for new developers:

Medium difficulty:

Infrastructure/etc discussions:

  • GSoC 2012
  • GSoC after Haskell.org
  • Mission statement? “To build an easy to use version control system based on a theory of patches”

Technical discussions:

  • Petr’s pathlib?
  • Packs
  • 2.8
  • Local branches
  • Diff/newline stuff

Discussion results


  • Ganesh and Florent: discussing 2.8 release (what patches to grab from mainland)
  • Eric: cleaning up mailing lists, bts templates, discussing GSoC 2012
  • Aditya: discussing GSoC 2012, grokking matchers
  • Owen: thinking about conflictors


  • Eric: updates to mailing lists, BTS template and milestones, GSoC 2012, some light screening/reviewing
  • Aditya: how to bring patch-index into darcs changes, discussing proposal, studying matchers code and changes code
  • Ganesh: 2.8-release argh, charsets! Unicode, argh!
  • Florent: 2.8, PatchSelectChoices for real-time dependency feedback (interactive), and darcs diff interactive
  • Owen: invconflictor/duplicate
  • Ian: camp stuff, talking about filename encoding.
  • Simon (remote): irc commit bot, contributor setup troubleshooting, making utf8 shell test easier to run


Strategy discussion (hunker down, no “grand soir”)

  • No more 5 yr Plan, No Big Push (cf. 2008 push for performance) - keep chipping away at the problem, cleaning things, making new features, eventually moving towards better

  • Still we try to communicate our strategy/priorities. The main emphasis these days is on cleaning Darcs up.

  • Hosting is important to us.

    • Development of hosting+GUIs will be focusing on library code that makes that work better, though may include actually writing code that uses that library to prove it works
    • GUIs seen as a subset of hosting for now
  • Emphasis on cleaning/reworking existing Darcs rather than any big bang wholesale replacements. Gradual progress.

  • Darcs 3 aim mainly to get conflicts right. Let’s not hit that Second System effect

  • GSoC 2013 mainly GUIs and Hosting (of course open to student suggestions)


  • Aditya: presented patch index, implementation of changes w/ index
  • Eric: patch774 and patch775, updated wiki to use markdown
  • Florent
  • Ganesh: Unicode progress!
  • Ian: more proofs (eg. commute two patches: always same answer)
  • Owen

How: Darcs hacking quick start

You’ll have more fun if you can hit the ground running, so please make sure you can do all of these things:

  1. darcs get –lazy http://darcs.net

  2. cabal configure; cabal build

  3. darcs send (your patch should wind up on the tracker)

    1. create a test patch (see http://darcs.net/report.html )
    2. see Msmtp for easiest setup or configure your MTA if you know how
    3. darcs send
    4. wait 10 minutes
    5. check the patch tracker http://bugs.darcs.net (Patches > Show Open)