Fix Nix Flake to continue building (#188)

The check phase for merlin had to be disabled as they depend on a
MERLIN_TEST_OCAML_PATH of a locally built ocaml.

Flake lock file updates:

• Updated input 'flake-utils':
    'github:numtide/flake-utils/b1d9ab70662946ef0850d488da1c9019f3a9752a?narHash=sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ%3D' (2024-03-11)
  → 'github:numtide/flake-utils/11707dc2f618dd54ca8739b309ec4fc024de578b?narHash=sha256-l0KFg5HjrsfsO/JpG%2Br7fRrqm12kzFHyUHqHCVpMMbI%3D' (2024-11-13)
• Updated input 'menhir-repository':
    'gitlab:fpottier/menhir/abb46d3d9c536bcbe30025f37474e3b4c8288590?host=gitlab.inria.fr&narHash=sha256-i/Xs6G1L/bZ1zj%2BLB5ehiaBC10ounc1koURV3vFolhI%3D' (2020-12-16)
  → 'gitlab:fpottier/menhir/d3d815e4f554da68b8c247241c8f8678926eecaa?host=gitlab.inria.fr&narHash=sha256-veB0ORHp6jdRwCyDDAfc7a7ov8sOeHUmiELdOFf/QYk%3D' (2023-12-31)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/c58b4a9118498c1055c5908a5bbe666e56abe949?narHash=sha256-YtlyfqOdYMuu7gumZtK0Kg7jr4OKfHUhJkZfNUryw68%3D' (2024-06-17)
  → 'github:nixos/nixpkgs/8eaee110344796db060382e15d3af0a9fc396e0e?narHash=sha256-iCGWf/LTy%2BaY0zFu8q12lK8KuZp7yvdhStehhyX1v8w%3D' (2025-09-19)

Author: georgyo

flake.lock

@@ -2,28 +2,36 @@
   description = "Merlin Nix Flake";
 
   inputs.flake-utils.url = "github:numtide/flake-utils";
-  inputs.nixpkgs.url = "github:nixos/nixpkgs";
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
   inputs.menhir-repository = {
     url = "gitlab:fpottier/menhir/20231231?host=gitlab.inria.fr";
     flake = false;
   };
 
-  outputs = { self, nixpkgs, flake-utils, menhir-repository }:
-    flake-utils.lib.eachDefaultSystem (system:
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+      menhir-repository,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
       let
         pkgs = nixpkgs.legacyPackages."${system}";
 
         # Build with OCaml 5.2
-        ocamlPackages = pkgs.ocaml-ng.ocamlPackages_5_2.overrideScope'
-          (_: osuper: {
+        ocamlPackages = pkgs.ocaml-ng.ocamlPackages_5_2.overrideScope (
+          _: osuper: {
             # Override menhirLib to the pinned version
             menhirLib = osuper.menhirLib.overrideAttrs (_: {
               version = "20231231";
               src = menhir-repository;
             });
 
             inherit (packages) merlin-lib dot-merlin-reader merlin;
-          });
+          }
+        );
 
         inherit (ocamlPackages) buildDunePackage;
 
@@ -32,16 +40,19 @@
           merlin-lib = buildDunePackage {
             pname = "merlin-lib";
             version = "dev";
-            src = ./.;
+            src = self;
             duneVersion = "3";
-            propagatedBuildInputs = with ocamlPackages; [ csexp ];
+            propagatedBuildInputs = with ocamlPackages; [
+              csexp
+              alcotest
+            ];
             doCheck = true;
           };
 
           dot-merlin-reader = buildDunePackage {
             pname = "dot-merlin-reader";
             version = "dev";
-            src = ./.;
+            src = self;
             duneVersion = "3";
             propagatedBuildInputs = [ ocamlPackages.findlib ];
             buildInputs = [ merlin-lib ];
@@ -51,7 +62,7 @@
           merlin = buildDunePackage {
             pname = "merlin";
             version = "dev";
-            src = ./.;
+            src = self;
             duneVersion = "3";
             buildInputs = [
               merlin-lib
@@ -60,25 +71,37 @@
               ocamlPackages.menhirSdk
               ocamlPackages.yojson
             ];
-            nativeBuildInputs = [ ocamlPackages.menhir pkgs.jq ];
+            nativeBuildInputs = [
+              ocamlPackages.menhir
+              pkgs.jq
+            ];
             nativeCheckInputs = [ dot-merlin-reader ];
             checkInputs = with ocamlPackages; [ ppxlib ];
-            doCheck = true;
+            doCheck = false; # Depends on a OxCaml
             checkPhase = ''
               runHook preCheck
+
               patchShebangs tests/merlin-wrapper
-              dune build @check @runtest
+              MERLIN_TEST_OCAML_PATH=${ocamlPackages.ocaml} \
+                dune build @check @runtest
+
               runHook postCheck
             '';
-            meta = with pkgs; { mainProgram = "ocamlmerlin"; };
+            meta = with pkgs; {
+              mainProgram = "ocamlmerlin";
+            };
           };
         };
-      in {
+      in
+      {
         inherit packages;
 
+        formatter = pkgs.nixfmt-tree;
+
         devShells.default = pkgs.mkShell {
           inputsFrom = pkgs.lib.attrValues packages;
           buildInputs = with ocamlPackages; [ merlin ];
         };
-      });
+      }
+    );
 }