Support dune 3.0

[smorimoto]

No description provided.

[booklearner]

I can start an attempt to do this if it's not already in progress. Feel free to reach out with any tips!

[talex5]

That would be great! The changes are mostly needed in dune, however.

Dune removed external-lib-deps because it was hard to implement, but this was because it tried to work out the dependencies without building the project first. For opam-dune-lint, that's not a problem.

The dune developers said:

First step for Dune would be to restore external-lib-deps, but as an output of the build itself (so it would become more precise, but at the cost of doing a build, which is fine).

[moyodiallo]

external-lib-deps is back for the next release of dune, as dune describe external-lib-deps(ocaml/dune#6045). But for the support 3.0, the lib dune-private-libs.dune-lang is removed since dune 3.0 and dune-lang is now private in dune.

[talex5]

external-lib-deps is back

Great - thanks!

dune-private-libs.dune-lang is removed

Ah. It looks like we just it for modifying the dune-project file with the updated packages. But they're just S-expressions, so we could do it with some other S-expression library. I think they only reason we care about it is to get the right formatting for the output, but perhaps there's a way to make dune fmt sort it out afterwards?

[moyodiallo]

For formatting dune files, there's a command dune format-dune-file <file>. It works for dune-project file too. But I don't know if it format the way it's needed in opam-dune-lint.

[tmcgilchrist]

@talex5 is right we can just use a simple s-expression library, maybe https://github.com/ocaml-dune/csexp since it has minimal dependencies. Then formatting via dune format-dune-file <file> 👍🏻

Ideally this should all get moved into dune/opam proper as an extra lint command.

[talex5]

csexp is a binary(ish) format. https://github.com/janestreet/parsexp is probably what you want.

[moyodiallo]

Yes, I confirm we need that lib.

[moyodiallo]

The command dune describe external-lib-deps has not alias like @install or @runtest. It prints out all the external dependencies by dir only. Is it a big deal for linting "with-test"? Because with this command we won't be able to do that.

opam-dune-lint/main.ml

Lines 82 to 83 in fa22308

	let build = get_libraries ~pkg ~target:"@install" |> to_opam_set ~project ~index in
	let test = get_libraries ~pkg ~target:"@runtest" |> to_opam_set ~project ~index in

[moyodiallo]

Mentioning this PR #46, it's not far from solving the issue.

[Lupus]

@moyodiallo it seems that there are only couple stylistic remarks in dune related PRs and those await your input. It's painful to match dependencies between opam and dune by hand, would be really awesome if this could go live!

[moyodiallo]

I admit this is a hack, dune doesn't release the necessary libraries. what we have is, printing out from dune (the PRs) the needed information. This is the same approximation as the current version.

[Lupus]

By current version you mean the master branch? I've just tried installing opam-dune-lint via opam and it suggested to downgrade dune.

[moyodiallo]

yes the master branch or the lastest release, the downgrade is normal.

[Lupus]

We're using dune 3.x, downgrading is not an option, but If I understand this correctly, the PRs in dune repo can unblock use of this tool with dune 3.x.

[moyodiallo]

Yes, that is the purpose. we're going to use this branch https://github.com/moyodiallo/dune.git#opam-dune-lint-testing, to test it on our CI ocurrent/ocaml-ci#811.

[smorimoto]

Do you have any plans to upstream changes to this repository?

[moyodiallo]

Do you have any plans to upstream changes to this repository?

Yes, #46 (comment)

[tmcgilchrist]

This also needs a new release to opam-repository @moyodiallo when dune support is in place.

[moyodiallo]

There is a new release now v0.3. This can be closed, thanks everyone for the effort.

[smorimoto]

Fantastic!

[tmcgilchrist]

As always @smorimoto please report any issue found to this repo.