Build src/ libraries from top-level dune or dune-project

[shakthimaan]

In Irmin src/, we have libraries such as irmin-mem, irmin-git, irmin-fs etc. I can build them from the command-line using:

$ dune build --only-packages irmin-layers,irmin,ppx_irmin

But, I would like to build the above from a Makefile using a dune build @target. I tried creating a irmin/dune file with the following:

(library
 (name        irmin_mem)
 (public_name irmin-mem)
 (libraries   irmin))

But, I get this error:

Error: Public library irmin-mem is defined twice:
- packages/irmin/dune:1
- packages/irmin/src/irmin-mem/dune:1

Where and how should I specify these libraries to be able to build them?
Reference:

1. https://github.com/mirage/irmin/tree/master/src

[bobot]

Do you tried to not add the dune file at the root and use dune build @src/target?

[shakthimaan]

I have the following dune-project in the top-level Irmin sources:

(lang dune 1.1)
(name irmin)

Where should I define target? Is there a minimal working example of both dune and dune-project that can build src/<libraries> by invoking a target in a Makefile?

[voodoos]

It is not clear to me what is your exact use case but you can ask Dune to build a specific library by specifying the correct cma target: dune build src/irmin/irmin.cma.

You can also use an alias to group the cma you need to build and call dune build @your/alias.

[shakthimaan]

Yes, we use an alias as mentioned here:

@dune b --workspace=$^ --release @buildbench

Source: https://github.com/stedolan/sandmark/blob/dunemark/Makefile#L4

But, the Irmin sources have multiple sub-packages, so I am not sure how to build them from a dune or dune-project file:
Source: https://github.com/stedolan/sandmark/tree/dunemark/packages/irmin

[ejgallego]

@shakthimaan you have several targets available for packages, usually dune build pkg.install tends to work well, but it only depends on the public parts of a package.

[Also note that this will build in dev mode which is not what you want for real use]

[voodoos]

@shakthimaan were you able to achieve your goal ?

[shakthimaan]

No. We are continuing to use opam, and switched to instead use a dev.opam file to install and manage the dependencies: https://github.com/ocaml-bench/sandmark/blob/main/dependencies/template/dev.opam.