opam-dune-lint gets the wrong package for some dependencies

[talex5]

e.g. with Eio, ocaml-ci is currently reporting:

eio_main.opam: changes needed:
  "fmt" {>= "0.9.0"}                       [from lib_eio_linux, lib_eio_posix, lib_eio_windows]
  "iomux" {>= "0"}                         [from lib_eio_posix]
  "logs" {>= "0.7.0"}                      [from lib_eio_linux]
  "uring" {>= "0"}                         [from lib_eio_linux]

But none of these directories is (directly) part of the eio_main package anyway.

For example, iomux is a dependency only of the eio_posix library, which is part of the eio_posix package (see https://github.com/ocaml-multicore/eio/blob/60e67472e3726192c4f6b9fbff81db5eb15b8a27/lib_eio_posix/dune#L10).

If I add (package eio_posix) to this, dune complains:

Error: This library has a public_name, it already belongs to the package eio_posix

And dune describe says:

  (library
   ((names (eio_posix))
    (extensions ())
    (package (eio_posix))
    (source_dir lib_eio_posix)
    (external_deps
     ((fmt required)
      (iomux required)))
    (internal_deps
     ((eio required)
      (eio.utils required)
      (eio.unix required)))))

So dune is reporting that iomux is part of eio_posix.

[moyodiallo]

This is a bug, by default opam-dune-lint also resolve the transitive dependencies because a public library could depends on a private library. It doesn't resolve the internal_deps which are public.

dune describe doesn't printing lib_eio_linux, lib_eio_posix, lib_eio_windows as internal_deps, because of the alternative select dune stanza.

(library
  (name eio_main)
  (public_name eio_main)
  (libraries
    (select linux_backend.ml from
            (eio_linux -> linux_backend.enabled.ml)
            (          -> linux_backend.disabled.ml))
    (select posix_backend.ml from
            (eio_posix -> posix_backend.enabled.ml)
            (          -> posix_backend.disabled.ml))
    (select windows_backend.ml from
            (eio_windows -> windows_backend.enabled.ml)
            (            -> windows_backend.disabled.ml))
    ))

This is why we're seeing this bug. It could be easily solved by sharing a list of all the public libraries.

[moyodiallo]

dune describe doesn't printing lib_eio_linux, lib_eio_posix, lib_eio_windows as internal_deps, because of the alternative select dune stanza.

the command dune describe external-lib-deps gives:

(library
  ((names (eio_main))
   (extensions ())
   (package (eio_main))
   (source_dir lib_main)
   (external_deps ())
   (internal_deps
    ((eio_linux optional)
     (eio_posix optional)
     (eio_windows optional)))))

My bad, my description above had some mistake. The internal optional public libs were resolve this is why the bug. Fixed here #54.

[moyodiallo]

The fix is deployed on ocaml-ci, is it OK to close this issue ? @talex5

[talex5]

That seems to work - thanks for the quick fix!

(it's now saying WARNING: can't find opam package providing "runtime_events", but that's another problem!)