odoc required by cram depending on objs/byte

[cuihtlauac]

Expected Behavior

> dune runtest
> echo $?
0

Actual Behavior

> dune runtest
File ".foo.objs/byte/_unknown_", line 1, characters 0-0:
Error: Program odoc not found in the tree or in PATH
 (context: default)
Hint: opam install odoc

Reproduction

1. Create and check into an opam switch with only ocaml and dune
2. Create a file dune-project with (lang dune 3.18)
3. Create empty files foo.ml and foo.t
4. Create the following dune file:

(library (name foo))

(cram
 (deps
  (glob_files .foo.objs/byte/*)))

5. Run dune runtest

Specifications

• Dune 3.18.0
• OCaml 5.3.0
• Ubuntu 24.10

Additional information

Local switch contents

base-bigarray         base
base-domains          base
base-effects          base
base-nnp              base
base-threads          base
base-unix             base
dune                  3.18.0
ocaml                 5.3.0
ocaml-base-compiler   5.3.0
ocaml-compiler        5.3.0
ocaml-config          3
ocaml-options-vanilla 1

[Alizter]

Here is a repro cram test:

  $ cat > dune-project <<EOF
  > (lang dune 3.18)
  > (package (name foo))
  > EOF

  $ cat > foo.ml
  $ cat > foo.t
  $ cat > dune <<EOF
  > (library
  >  (public_name foo))
  > (cram
  >  (deps
  >   (glob_files .foo.objs/byte/*)))
  > EOF

  $ PATH=$(dirname -- $(command -v ocaml))\
  > :$(dirname -- $(command -v dune))\
  > :$(dirname -- $(command -v cat))\
  > :$(dirname -- $(command -v sh))

  $ dune build @runtest
  File "_doc/_odoc/pkg/foo/_unknown_", line 1, characters 0-0:
  Error: Program odoc not found in the tree or in PATH
   (context: default)
  Hint: opam install odoc
  [1]

[Alizter]

Here is the reason:

  $ dune build @runtest --debug-dependency-path
  File "_doc/_odoc/pkg/foo/_unknown_", line 1, characters 0-0:
  Error: Program odoc not found in the tree or in PATH
   (context: default)
  -> required by _build/default/_doc/_odoc/pkg/foo/page-index.odoc
  -> required by alias _doc/_odoc/pkg/foo/.odoc-all
  -> required by _build/default/.foo.objs/byte/foo.odoc
  -> required by alias foo
  -> required by alias runtest
  Hint: opam install odoc
  [1]

We are storing foo.odoc in byte/.foo.objs so naturally this requires odoc to build. You can fix your glob by excluding foo.odoc.

[Alizter]

One way you can exclude is to do:

   (glob_files .foo.objs/byte/foo.c*)

since all the files you are interested in have a .c in this case.

[cuihtlauac]

Brilliant! Thanks for the workaround. BTW, don't you think it would be nice to have something like %{objs:foo}? Somehow similar to %{cma:foo}

[Alizter]

I'm not sure what exactly we would include in such a %{objs:_} variable. i.e. bytecode or native or both?

However I suppose the more idiomatic way to do what you want would be:

  (deps %{cmo:foo} %{cmi:foo}))

if there are other compilation artefacts that you require and are not listed here: https://dune.readthedocs.io/en/stable/advanced/variables-artifacts.html#variables-for-artifacts

then we could definitely consider adding them.

[rgrinberg]

Maybe we could the odoc artifacts into their own object directory. Shouldn't be too hard and it does seem like the safer default.