Fix build with dune package management

[Sudha247]

This PR adds some dependencies that fix building with dune package management. Happy to submit a PR to opam-repository retroactively changing it for released versions if it's appropriate.

[bclement-ocp]

Hi and thanks for the PR!

Can you clarify what commands you are using that are failing? These dependencies should only be required for building the JS version of alt-ergo, which is not intended to be built through opam.

[Sudha247]

Thanks for the response! So my usual workflow is this --

$ dune pkg lock # To determine dependencies
$ dune build # Install dependencies and build the project

Doing this on the main branch results in the following error message:

File "src/lib/dune", line 44, characters 4-10:
44 |     Config Emap Gc_debug Hconsing Hstring Iheap Lists Loc
         ^^^^^^
Error: Module Config doesn't exist.
Error: Multiple rules generated for               
_build/default/src/bin/text/Main_text.exe:
- src/bin/text/dune:7
- file present in source tree
-> required by alias default
Hint: rm -f src/bin/text/Main_text.exe
File "src/bin/js/dune", line 4, characters 32-47:  
4 |   (libraries    alt_ergo_common zarith_stubs_js)
                                    ^^^^^^^^^^^^^^^
Error: Library "zarith_stubs_js" not found.
-> required by _build/default/src/bin/js/main_text_js.bc
-> required by alias src/bin/js/all
-> required by alias default
File "src/bin/js/dune", line 32, characters 61-76: 
32 |   (libraries    worker_interface zarith_stubs_js js_of_ocaml js_of_ocaml-lwt)
                                                                  ^^^^^^^^^^^^^^^
Error: Library "js_of_ocaml-lwt" not found.
-> required by _build/default/src/bin/js/worker_example.bc
-> required by alias src/bin/js/all
-> required by alias default
File "src/bin/js/dune", line 21, characters 77-92: 
21 |   (libraries    worker_interface alt_ergo_common zarith_stubs_js js_of_ocaml js_of_ocaml-lwt)
                                                                                  ^^^^^^^^^^^^^^^
Error: Library "js_of_ocaml-lwt" not found.
-> required by _build/default/src/bin/js/worker_js.bc
-> required by alias src/bin/js/all
-> required by alias default
File "src/bin/js/dune", line 14, characters 28-41: 
14 |   (libraries    js_of_ocaml data-encoding)
                                 ^^^^^^^^^^^^^
Error: Library "data-encoding" not found.
-> required by library "worker_interface" in _build/default/src/bin/js
-> required by
   _build/default/src/bin/js/.worker_interface.objs/native/worker_interface.cmx
-> required by _build/default/src/bin/js/worker_interface.a
-> required by alias src/bin/js/all
-> required by alias default
Error: Program js_of_ocaml not found in the tree or in PATH
 (context: default)
-> required by _build/default/src/bin/js/main_text_js.bc.js
-> required by alias src/bin/js/all
-> required by alias default
Hint: opam install js_of_ocaml-compiler
File "src/bin/js/dune", line 35, characters 19-34: 
35 |   (preprocess (pps js_of_ocaml-ppx lwt_ppx))
                        ^^^^^^^^^^^^^^^
Error: Library "js_of_ocaml-ppx" not found.
-> required by _build/default/src/bin/js/worker_example.pp.ml
-> required by alias src/bin/js/all
-> required by alias default
File "src/plugins/AB-Why3/dune", lines 8-12, characters 0-84:
 8 | (menhir
 9 |   (infer    false)
10 |   (flags    --fixed-exception)
11 |   (modules  why3_parser)
12 | )
Error: the code back-end requires the type of every nonterminal symbol to be
known. Please specify the type of every symbol via %type declarations, or
enable type inference (look up --infer in the manual).
Type inference is automatically enabled when Menhir is used via Dune,
provided the dune-project file says (using menhir 2.0) or later.

I suspect this is because dune build tries to build the whole repo.

[bclement-ocp]

Doing this on the main branch results in the following error message:

You should be using the next branch (which is the default branch for the repository), not the main branch which is an old branch (the naming is confusing, I know…).

[bclement-ocp]

That said, you are right that dune build will try to build everything (including js stuff), as does make (I usually only do either dune exec -- alt-ergo or dune build @runtest).

We can't really add those as dependencies, because they are not used unless buildin with JS, and it's not really appropriate to add them as with-dev dependencies either (for the same reason). Ideally, we should have a separate alt-ergo-js package to attach these dependencies to, but I think we had problems with this in the past (although I don't recall exactly what).