How to use ocaml 5.1.1

[bikallem]

I am attempting to use opam-nix with ocaml 5.1.1. I have done the following:

1. nix flake init -t github:tweag/opam-nix
2. nix develop
3. ocaml -vnum
   The OCaml toplevel, version 5.1.1~rc1
4. Change ocaml-base-compiler="5.1.1" in flake.nix. I get the following error:

error:
       … while calling the 'derivationStrict' builtin

         at /builtin/derivation.nix:9:12: (source not available)

       … while evaluating derivation 'nix-shell'
         whose name attribute is located at /nix/store/q3l9x3ncgi0hppw0i65ki9jrxj8kmgac-source/pkgs/stdenv/generic/make-derivation.nix:302:7

       … while evaluating attribute 'buildInputs' of derivation 'nix-shell'

         at /nix/store/q3l9x3ncgi0hppw0i65ki9jrxj8kmgac-source/pkgs/stdenv/generic/make-derivation.nix:349:7:

          348|       depsHostHost                = lib.elemAt (lib.elemAt dependencies 1) 0;
          349|       buildInputs                 = lib.elemAt (lib.elemAt dependencies 1) 1;
             |       ^
          350|       depsTargetTarget            = lib.elemAt (lib.elemAt dependencies 2) 0;

       error: builder for '/nix/store/4xigsfhv28fgyy8m2hrvb6f84pyl0c3p-resolve.drv' failed with exit code 20;
       last 5 log lines:
       > [ERROR] No solution including optional dependencies for ocaml-base-compiler.5.1.1 & utop:   * Missing dependency:
       >             - ocaml-base-compiler > 5.2.0
       >             no matching version
       >
       >
       For full logs, run 'nix log /nix/store/4xigsfhv28fgyy8m2hrvb6f84pyl0c3p-resolve.drv'

How do I use ocaml 5.1.1 with opam-nix?

[balsoft]

Hi! I have updated opam-repository in opam-nix, which should fix the issue once you update the version (with nix flake update opam-nix in your repo). Could you confirm that the fix works?

In the future, you can update opam-repository yourself a-la this:

  inputs = {
    opam-nix.url = "github:tweag/opam-nix";
    opam-nix.inputs.opam-repository.follows = "opam-repository";
    flake-utils.url = "github:numtide/flake-utils";
    nixpkgs.follows = "opam-nix/nixpkgs";
    opam-repository.url = "github:ocaml/opam-repository";
    opam-repository.flake = false;
  };

[bikallem]

Thanks. It seems to do the trick.