Is there a way to specify that a dependency should be pulled from a git repository with Dune?

Ecosystem
1

I’m working on a set of packages which all depend on a common base package. The base package is not yet in Opam because I’m still polishing it.

Until now, I’ve been vendoring that package as a git submodule in the packages which depend on it, but I’m not particularly happy with this solution.

In Python, for example, one can specify that a dependency comes from a git repository with syntax like this: some-package @ git+https://github.com/some/repository

Is there a way to do something similar with Dune?

1 Like
2

I figured out I can make this work for development purposes using opam pin, but this ostensibly has to be configured per-machine.

I see that there is also a way to pin a dependency like this in an opam file, but I am not sure how this will interact with dune, which tends to rewrite the opam file.

3

You can use an opam template file. Dune will insert its contents into the generated final opam file. Eg ocaml-decimal/decimal.opam.template at main · yawaramin/ocaml-decimal · GitHub

2 Likes
4

This can also be done with dune package management. If your dependencies are in your dune-project file, then add something like this to dune-project:

(pin
 (package
  (name <name>)
  (version <version-dune-will-see>))
 (url git+https://github.com/...))

You still also need to include the dependency on the package in the (depends ...) section of dune-project. Then run dune pkg lock to solve dependencies and then future runs of dune build will download and build the dependency from its git repo.

3 Likes
5

Read more here.

1 Like
6

Thanks @yawaramin and @gridbugs. I’ll experiment with both of these approaches and see which one tickles my fancy.