Add basic .devcontainer setup

[pgiarrusso-sl]

No description provided.

[github-actions]

Performance summary for https://github.com/SkylabsAI/workspace/actions/runs/19040274869

Relative	Master	MR	Change	Filename
+0.00%	116596.1	116596.1	+0.0	total
-0.00%	22020.0	22019.8	-0.1	├ translation units
+0.00%	94576.2	94576.2	+0.0	└ proofs and tests

Full Results

Relative	Master	MR	Change	Filename
+0.00%	116596.1	116596.1	+0.0	total
-0.00%	22020.0	22019.8	-0.1	├ translation units
+0.00%	94576.2	94576.2	+0.0	└ proofs and tests

[rlepigre-skylabs-ai]

For reference, here is what we used to have before:

{
	"name": "FM Default",
	"image": "ghcr.io/skylabsai/skylabs-fm:fm-default",

	"customizations": {
		"vscode": {
			"settings": {
				"vscoq.path": "/workspaces/skylabs-fm/_build/install/default/bin/vscoqtop"
			},
			"extensions": [
				"maximedenes.vscoq",
				"ocamllabs.ocaml-platform"
			]
		}
	},
	"mounts": [
		"source=${localEnv:HOME}/.cache/dune,target=/home/coq/.cache/dune,type=bind,consistency=cached"
	]
}

[rlepigre-skylabs-ai]

I think it would make sense to at least change the name.

Maybe we should also bring in the cache mounting we had in the config I posted above, and the OCaml extension?

We were also using a different vsrocq extension it seems?

[pgiarrusso-sl]

What I sent is simplified from https://github.com/SkylabsAI/fm-ci/blob/main/devcontainer/devcontainer.json, documented in
https://github.com/SkylabsAI/fm-ci/blob/main/devcontainer/README.md.

• "maximedenes.vscoq" got renamed to vsrocq, we can merge the other extensions — and drop versions from vsrocq
• should we share the cache with the host? That seems iffy. It'll work, but I'd rather clear the devcontainer cache whenever the image changes.

[pgiarrusso-sl]

ah, https://containers.dev/implementors/json_reference/#variables-in-devcontainerjson supports defaults! Then we can maybe have our cake and eat it too — at least if nested references work:

"source=${localEnv:DUNE_CACHE_DOCKER:${localEnv:HOME}/.cache/dune},target=/home/coq/.cache/dune,type=bind,consistency=cached"

EDIT: I can check devcontainers/spec#255.

[rlepigre-skylabs-ai]

I only care that the cache used in the devcontainer is shared among different instances of the devcontainer.

I guess we could eventually allow people to locally mount the NFS cache? Though this might not be an improvement depending on the network.

[github-actions]

Performance summary for https://github.com/SkylabsAI/workspace/actions/runs/19303425469

Relative	Master	MR	Change	Filename
-0.00%	116925.3	116925.3	-0.0	total
-0.00%	22013.8	22013.9	-0.0	├ translation units
+0.00%	94911.5	94911.5	+0.0	└ proofs and tests

Full Results

Relative	Master	MR	Change	Filename
-0.00%	116925.3	116925.3	-0.0	total
-0.00%	22013.8	22013.9	-0.0	├ translation units
+0.00%	94911.5	94911.5	+0.0	└ proofs and tests

[github-actions]

Performance summary for https://github.com/SkylabsAI/workspace/actions/runs/19305940636

Relative	Master	MR	Change	Filename
+0.00%	116925.3	116925.3	+0.0	total
+0.00%	22013.8	22013.8	+0.0	├ translation units
+0.00%	94911.5	94911.5	+0.0	└ proofs and tests

Full Results

Relative	Master	MR	Change	Filename
+0.00%	116925.3	116925.3	+0.0	total
+0.00%	22013.8	22013.8	+0.0	├ translation units
+0.00%	94911.5	94911.5	+0.0	└ proofs and tests

[pgiarrusso-sl]

We discussed and tested this together, so merging.