OCaml Hack Event - 4.06 opam fixes & compiler projects

The recent OCaml 4.06 release has made the long-awaited switch to immutable strings by default. However, this has resulted in a significant number of opam packages requiring modifications to build - we are hosting an OCaml Hack Evening on Thursday 7th December from 19:00-22:30 at Pembroke College, Cambridge to fix as many as possible.

Please indicate your interest via the Doodle by Thursday 30th November.

If you cannot physically attend, but would like to help fix up packages in the meantime / during the event in your local timezone, check Obi for the failures. Fix all the red things :stuck_out_tongue:

When: Thursday 7 December 2017, 19:00 - 22:30
Where: The Thomas Gray Room, Pembroke College, Cambridge CB2 1RF
Who: anyone interested in improving OCaml. Knowledge of OCaml programming will obviously be helpful, but prior experience of working on OCaml internals isn’t necessary
Refreshments: Finger buffet in hack room
What: ​Fixing opam packages, ​fixing bugs, implementing new features, learning about OCaml internals
Wiki: https://github.com/ocamllabs/compiler-hacking/wiki

The OCaml 4.06 release featured safe-string as the default rather than optional as per previous releases. The focus of this event will be to work on the opam repository to fix up as many packages as possible, and also to publish a guide on ocamllabs.io detailing how to migrate your packages for wider use.

​As well as fixing up opam packages, you can find information on mini projects and other compiler projects on the wiki.​

The evening will also feature a short (5-10 min) presentation about the recent MirageOS Marrakech Hack Retreat.


Anyone who can’t make it to Cambridge – we could congregate in #ocaml as well :slight_smile:


I started using OCaml 3 days back. I got interested in the Mirage OS project and started learning OCaml for that. I was wondering if I can contribute anything to this Hack Event (small patches,documentation etc) to learn more about OCaml or if there is a prerequisite.

Please note I have programmed in Haskell for nearly 2 years now, and in some low level compiler projects. So I didn’t find OCaml too different.

It’s a bloodbath! :stuck_out_tongue:


The good news is that the evening has been productive, and 100s of opam packages have been fixed by our wine-drinkin^H^H^Hhard working volunteers at the Pembroke evening. Congratulations to our newest contributor minishrink on her first opam-repository PRs!

The bad news is that the 50 or so PRs appear to have caused a slight hiccup in the Travis and DataKit CIs causing the GitHub API to get annoyed with us :slight_smile: I’ll fix this in the morrow when the rate limits calm down.

The even worse news is that we just ran out of wine…


:wine_glass: Oh, no! :wine_glass: