Re: OCaml package `ocaml-zarith` not working / Guix installed `ocamlc` not picking up installed libraries (addendum 1)

[Zelphir Kaltstahl <zelphirkaltstahl@posteo.de>]

On 30.12.24 18:50, Zelphir Kaltstahl wrote:
>
> Hello Guix users,
>
> I am facing a problem trying to use Guix to install Ocaml packages.
>
> I was implementing a simple recursive factorial function, as part of learning 
> the language, and tested what would happen, if I calculated factorial of 100 
> ... Result: 0. "Ah!" I thought, "all I need to do is get that Zarith package I 
> have been reading about before, and import that in my code!". So I added it to 
> my manifest.scm file, which I use for a `guix shell`, and expected the Ocaml 
> compiler to naturally pick up packages installed via guix, since the Ocaml 
> compiler ocamlc is also installed using guix. However, it seems this is 
> dysfunctional currently and ocamlc does not realize that the library is in 
> fact installed. I am not sure where it is looking for libraries.
>
> Here is how to reproduce:
>
> ~~~~guix-env/channels.scm~~~~
> (list (channel
>          (name 'guix)
>          (url"https://git.savannah.gnu.org/git/guix.git")
>          (branch "master")
>          (commit
>            "4473f8ae902c2192cab6919363a9101ce9861e45")
>          (introduction
>            (make-channel-introduction
>              "9edb3f66fd807b096b48283debdcddccfea34bad"
>              (openpgp-fingerprint
>                "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))
> ~~~~
>
> ~~~~guix-env/manifest.scm~~~~
> (specifications->manifest
>   '("ocaml"
>     "ocaml-utop"
>     "dune"
>     ;; "opam"  ; using guix to install packages, should not need opam
>     "bash"
>     "ocaml-zarith"))
> ~~~~
>
> ~~~~main.ml~~~~
> open Z
>
> let factorial n =
>    let rec iter n =
>      if n < (of_int 2)
>      then of_int 1
>      else mul n (iter (sub n (of_int 1)))
>    in
>      iter (of_int n)
>
>
> let _ = 5 |> factorial |> to_string |> print_endline
> let _ = 100 |> factorial |> to_string |> print_endline
> ~~~~
>
> ~~~~command~~~~
> guix time-machine --channels=guix-env/channels.scm -- shell --check --manifest=guix-env/manifest.scm -- bash -c 'ocamlc -c main.ml -o main.byte'
>
> guix shell: checking the environment variables visible from shell '/bin/bash'...
> guix shell: All is good!  The shell gets correct environment variables.
> File "main.ml", line 1, characters 5-6:
> 1 | open Z
>           ^
> Error: Unbound module Z
> ~~~~

I would also like to add, that utop _does_ pick up the library and that in utop 
I can:

~~~~in utop~~~~
#require "zarith";;
~~~~

And work with its functions.

So this really seems to be about ocamlc.

-- 
repositories:https://notabug.org/ZelphirKaltstahl,https://codeberg.org/ZelphirKaltstahl