Support pin-depends

[ocurrent]

Support pin-depends

[Julow]

We tried to study a simple/naive fix yesterday:
We could use git ls-remote to query the last rev of each pin-depends (in a job placed outside of Analyse's cache). The rev could then be inserted in the command installing them, invalidating Docker's cache if that changes.
The problem is that opam files and opam show are very hard to parse. To solve that we should use Opam's opam-format library.

[talex5]

Note: another way to depend on dev versions is to use git submodule to add the exact commit you want to your project. ocaml-ci will automatically fetch these submodules (using git clone --recursive) and dune will automatically build against them.

[pascutto]

Note: another way to depend on dev versions is to use git submodule to add the exact commit you want to your project. ocaml-ci will automatically fetch these submodules (using git clone --recursive) and dune will automatically build against them.

If we wanted to depend on a specific commit we could also pin-depend on that specific commit, and the CI works well in that case too.

[talex5]

Note that pin-depends is broken at the moment as the new solver (in #167) only has access to the Git clone and opam-repository. I guess we'll need to implement fetching of pin-depends manually somehow.

[craigfe]

Title changed to reflect that this is now a more general issue.

[talex5]

pin-depends with a commit hash is working again now. I don't think we'll support pinning to branches any time soon.

[pascutto]

It seems like there is an issue when pinning to a repo where the opam file is not at the root (maybe it's unrelated to pinning?), it can't find the opam file thus fails during analysis.

[talex5]

Do you have a link to an example? ocaml-ci currently assumes the opam file is at /$name.opam, although I think opam also allows some other forms.

[pascutto]

Here's one: https://ci.ocamllabs.io/github/vocal-project/vocal/commit/363a91d49e1e89c202d5656c088f3a8ca538f68c/variant/(analysis)
The opam file is under a opam/ folder

[talex5]

I've pushed a fix - should be working now!