OCaml Changelog

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Support for dune shell completions for bash and zsh has just landed in the Dune Developer Preview!

Running the installer adds a snippet to your shell config (e.g. ~/.bashrc) that installs a completion handler for dune. The completion script was taken from here, and that page has some information about how the script was generated. Once it's installed the completions will work any time dune is typed at the start of a command, so you can still use the completions when running a version of Dune installed with Opam or your system package manager after installing the Dune Developer Preview.

Currently only command completions are supported. So you can run:

$ dune c<TAB>
cache  clean  coq

...or:

$ dune build -<TAB>
--action-stderr-on-success
--action-stdout-on-success
--always-show-command-line
--auto-promote
--build-dir
--build-info
--cache
...

But if you run dune build <TAB> then it will still suggest local files rather than build targets.

Try it out!

Getting started is easy:

$ curl -fsSL https://get.dune.build/install | sh
$ source ~/.bashrc  # or: source ~/.zshrc
$ dune <TAB>
build
cache
clean
coq
describe
diagnostics
exec
...

Hello folks! 👋

We'd like to welcome everyone to try and play with the Dune Developer Preview! 🎉

This experimental nightly release of dune includes a lot of improvements, including the much expected package management features, and it can be installed from that website or by using the new installation script:

$ curl -fsSL https://get.dune.build/install | bash

In a few seconds you should be ready to OCaml by calling dune:

You can also watch and share this demo on X and Mastodon.

Please try it out and let us know what you think 🙏

📅 You can book a feedback call with us here

📝 You can submit feedback using this form

🐛 You can submit issues to Github on ocaml/dune

Changes since last update

The Dune shared cache has been enabled by default. We're starting off by caching all downloads and dependencies.

We have improved support for dev tools. We're working to streamline this but in the latest binary you can:

• Configure your LSP (in Neovim, Vim, Emacs, etc) to call dune tools exec ocamllsp to get LSP support for your projects out of the box – this may take a little bit the first time it builds the LSP for a compiler version, but it's pretty much instant afterwards.

• Call dune fmt to get your project formatted – remember to add an .ocamlformat file if you don't have one yet. An empty one is enough.

• Call dune ocaml doc to get documentation built

What's next?

We're looking forward to streamlining the DX, working on better dependency locks, and looking into supporting Windows.

In particular, we're considering work on a few things:

• dune create <repo> – to let the community create templates that can be easily used from within dune
• dune pkg fetch – to prefetch packages and prepare a repository for working in offline mode
• dune build @deps - to build all dependencies, useful for staged builds in Dockerfiles
• dune pkg add <name> - to make adding packages straightforward
• a short-hand syntax for pins on github
• and more!

If you've got any ideas, we'd love to hear them, so please open a feature request on Github 🙏

Other updates

FunOCaml Presentation

At FunOCaml we had a last-minute opportunity to present the work being done on Dune and we used it to introduce the Developer Preview to the community, and even tested Package Management live with suggestions from the audience (thanks @anmonteiro and Paul-Elliot for participating!) – you can watch it on Twitch.

New design

We're working with @Claire_Vandenberghe on redesigning the Developer Preview website so that it'd feel like a seamless extension of OCaml.org – in this current iteration we've made it easier to get started and we're putting the FAQ front and center.

We'll be iterating on this design in the coming weeks until it fits perfectly within the OCaml.org design system 🎨

You can check the new website here: https://preview.dune.build

Upcoming Blog posts

In the near future we'll be publishing blog posts about the Developer Preview and Package Management, which we're working on with @professor.rose 👏

As we prepare for the public beta, we're ramping up the DX interviews and ensuring the first few users will have a fun, productive experience with the Developer Preview.

📥 If you signed up for the Dev Preview back in May, check your inbox for a link and instructions to schedule your DX interview with us.

Here's a sample video on (Mastodon or X) where you can see us building the Riot project on a machine that does not have OCaml installed. It is pretty neat!

Seriously, big shoutout to the Dune team at Tarides[0] and Jane Street[1] who have been doing a phenomenal job 👏 ✨ 🐫

So here's what getting started with OCaml looks like using the Dune Developer Preview as of today (August 19 2024):

1. get dune from our binary distribution – we'll soon make this public!
2. run dune pkg lock in your favorite project
3. run dune build

That's it. No need to install anything else! Dune will see that lock file, fetch, and build all necessary dependencies.

🗺️ These are some strong steps towards the OCaml Platform vision for 2026 that we are actively working towards. If you have any thoughts or feedback please let us know!

There are more improvements coming that will help remove friction to get started and create a delightful experience. Both of these things we strongly believe will help onboard new users to the OCaml world.

Here's a few in the works:

• Various DX improvements – from new outputs to simplified workflows, we want to make using Dune just delightful.

• Bundled support for dev tools (OCamlFormat, odoc, LSP) – the default toolset will be available without any extra steps! Just call dune fmt and it works. No need to manually install anything else.

• Automatic dependency locking – when building, and even in watch mode, Dune will lock your dependencies by default and keep the lock up to date.

• Cross-project caching – by default we'll enable a local Dune cache across the system, so you never rebuild the same dependency, even across projects.

• Signed binaries with certificates of origin – we care deeply about security and want to make sure that any binary we ship can be easily verified and tracked back to its sources.

Stay tuned! 👋

PS: here's a longer video on (Mastodon or X) showing you the setup for OCaml from zero, creating a new project, and adding a dependency, all within ~5 minutes

[0] @emillon @Leonidas @gridbugs @tmattio @maiste . Ambre Suhamy, Alpha Diallo [1] @rgrinberg