Need help verifying bug: ocaml-lsp-server is compiled with wrong compiler version?

[kentookura]

I am experiencing a bug with ocamllsp and it was indicated to me that this may be due to a version mismatch between the compiler that builds my project and the compiler that compiled the language server:
ocaml/merlin#1860

What do I need to do to verify and fix this?

Thanks!

[balsoft]

Can you share your project? Are you building everything with opam-nix? Is it all part of a single scope?

[kentookura]

Of course:

Full repo: https://git.sr.ht/~jonsterling/ocaml-forester/tree/lsp

dune-project:

(lang dune 3.13)

;;; SPDX-FileCopyrightText: 2024 The Forester Project Contributors
;;;
;;; SPDX-License-Identifier: GPL-3.0-or-later

(using menhir 3.0)

(name forester)

(authors "Jonathan Sterling")

(maintainers "Jonathan Sterling")

(version 5.0)

(generate_opam_files true)

(implicit_transitive_deps false)

(source
 (sourcehut jonsterling/ocaml-forester))

(bug_reports https://todo.sr.ht/~jonsterling/forester)

(homepage https://sr.ht/~jonsterling/forester/)

(license GPL-3.0-or-later)

(package
 (name forester)
 (synopsis "A tool for tending mathematical forests")
 (depends
  (menhir
   (>= 20240715))
  (ocamlgraph
   (>= 2.1.0))
  (ocaml
   (>= 5.2.0))
  dune
  ppx_deriving
  (cmdliner
   (>= 1.2.0))
  dune-build-info
  (iri
   (>= 1.0.0))
  (uucp
   (>= 15.1.0))
  (eio_main
   (>= 1.1))
  (ptime
   (>= 1.1.0))
  (asai
   (>= 0.3.0))
  (yuujinchou
   (>= 5.2.0))
  (bwd
   (>= 2.3.0))
  (algaeff
   (>= 2.0.0))
  (yojson
   (>= 2.1.2))
  (toml
   (>= 7.1.0))
  (repr
   (>= 0.7.0))
  (ppx_repr
   (>= 0.7.0))
  (uri
   (>= 4.4.0))
  (pure-html
   (>= 3.6.1))
  (base64
   (>= 3.5.1))
  (datalog
   (>= 0.7))
  (cid
   (>= 0.1.0))
  (lsp
    (>= 0.19.0))
  (ppx_yojson_conv
    (>= 0.17.0))))

opam file:

# This file is generated by dune, edit dune-project instead
opam-version: "2.0"
version: "5.0"
synopsis: "A tool for tending mathematical forests"
maintainer: ["Jonathan Sterling"]
authors: ["Jonathan Sterling"]
license: "GPL-3.0-or-later"
homepage: "https://sr.ht/~jonsterling/forester/"
bug-reports: "https://todo.sr.ht/~jonsterling/forester"
depends: [
  "menhir" {>= "20240715"}
  "ocamlgraph" {>= "2.1.0"}
  "ocaml" {>= "5.2.0"}
  "dune" {>= "3.13"}
  "ppx_deriving"
  "cmdliner" {>= "1.2.0"}
  "dune-build-info"
  "iri" {>= "1.0.0"}
  "uucp" {>= "15.1.0"}
  "eio_main" {>= "1.1"}
  "ptime" {>= "1.1.0"}
  "asai" {>= "0.3.0"}
  "yuujinchou" {>= "5.2.0"}
  "bwd" {>= "2.3.0"}
  "algaeff" {>= "2.0.0"}
  "yojson" {>= "2.1.2"}
  "toml" {>= "7.1.0"}
  "repr" {>= "0.7.0"}
  "ppx_repr" {>= "0.7.0"}
  "uri" {>= "4.4.0"}
  "pure-html" {>= "3.6.1"}
  "base64" {>= "3.5.1"}
  "datalog" {>= "0.7"}
  "cid" {>= "0.1.0"}
  "lsp" {>= "0.19.0"}
  "ppx_yojson_conv" {>= "0.17.0"}
  "odoc" {with-doc}
]
build: [
  ["dune" "subst"] {dev}
  [
    "dune"
    "build"
    "-p"
    name
    "-j"
    jobs
    "@install"
    "@runtest" {with-test}
    "@doc" {with-doc}
  ]
]
dev-repo: "git+https://git.sr.ht/~jonsterling/ocaml-forester"

flake.nix:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    opam-repository.url = "github:ocaml/opam-repository";
    opam-repository.flake = false;
    opam-nix.url = "github:tweag/opam-nix";
  };
  outputs =
    {
      self,
      flake-utils,
      opam-nix,
      nixpkgs,
      opam-repository,
    }@inputs:
    let
      package = "forester";
    in
    flake-utils.lib.eachDefaultSystem (
      system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        on = opam-nix.lib.${system};
        devPackagesQuery = {
          ocaml-base-compiler = "5.2.0";
          ocaml-lsp-server = "*";
          ocamlformat = "*";
          memtrace = "*";
        };
        query = devPackagesQuery // { };
        scope = on.buildOpamProject' { repos = [ "${opam-repository}" ]; } ./. query;
        overlay = final: prev: {
          ${package} = prev.${package}.overrideAttrs (_: {
            doNixSupport = false;
          });
        };
        scope' = scope.overrideScope' overlay;
        main = scope'.${package};
        devPackages = builtins.attrValues (pkgs.lib.getAttrs (builtins.attrNames devPackagesQuery) scope');
      in
      {
        legacyPackages = scope';
        packages.default = main;
        devShells.default = pkgs.mkShell {
          inputsFrom = [ main ];
          buildInputs = devPackages ++ [
            pkgs.topiary
            pkgs.reuse
          ];
        };
      }
    );
}

[balsoft]

This seems to be correct, and it's definitely building both forester and ocaml-lsp-server with the same ocaml compiler. The symbol picker (workspace/symbol) also seems to work for me (I'm using Helix). I just cloned the project, checked out the lsp branch, then direnv allow and dune build:

Perhaps you need to direnv reload, run dune build again, or start your editor from a new shell to refresh some non-invalidated cache somewhere?

[kentookura]

This does not seem to be the problem. My environment is definitely up to date, and if I try to use the symbol picker in helix, it reports "protocol error: InternalError: uncaught exception"...

[kentookura]

I just pushed a new flake.lock file, to make sure we are debugging the same environment.

[balsoft]

I just tried with your updated flake.lock; I entered a "pure" shell with nix develop --ignore-environment, ran Helix with nix run np#helix, and was still able to use the workspace_symbol_picker with no issues.

Is there a chance you have ocaml-lsp-server or merlin or something like that installed globally that might be "poisoning" your environment? Can you try inside the pure shell with nix develop --ignore-environment ?

[kentookura]

No, the lsp and merlin are not available in the global environment. Running nix develop --ignore-environment and nix run nixpkgs#helix results in the same error.

[balsoft]

This is quite weird. I was able to get it working easily on another (NixOS) machine. Here are the exact things I did:

$ git clone https://git.sr.ht/~jonsterling/ocaml-forester
Cloning into 'ocaml-forester'...
remote: Enumerating objects: 7951, done.
remote: Counting objects: 100% (721/721), done.
remote: Compressing objects: 100% (399/399), done.
remote: Total 7951 (delta 511), reused 363 (delta 315), pack-reused 7230 (from 1)
Receiving objects: 100% (7951/7951), 2.47 MiB | 31.96 MiB/s, done.
Resolving deltas: 100% (5377/5377), done.
$ cd ocaml-forester
$ git checkout lsp
branch 'lsp' set up to track 'origin/lsp'.
Switched to a new branch 'lsp'
$ nix develop --ignore-environment
bash-5.2$ dune build
File "lib/compiler/Grammar.mly", line 15, characters 16-23:
Warning: the token COMMENT is unused.
File "Grammar.mly", line 15, characters 16-23:
Warning: the token COMMENT is unused.
Read 92 sample input sentences and 19 error messages.
bash-5.2$ nix run nixpkgs#helix
SPACE+f lib/forest/Forest.ml RET SPACE+S

And it gave me the list of all symbols in the workspace just fine.

[kentookura]

Hmm, oh well. It's not urgent at all. If this persists after the issue on the merlin repo is solved, I might try to get it working again, but in the meantime, you don't need to waste any more time on this. Thanks for your quick respones!

[kentookura]

Just letting you know that this still occurs on version 1.20.1 of the LSP.