chore(nix): remove flake-utils (#873)

Author: anmonteiro

flake.lock

@@ -3,92 +3,98 @@
 
   inputs = {
     nix-filter.url = "github:numtide/nix-filter";
-    flake-utils.url = "github:numtide/flake-utils";
-    nixpkgs = {
-      url = "github:nix-ocaml/nix-overlays";
-      inputs.flake-utils.follows = "flake-utils";
-    };
+    nixpkgs.url = "github:nix-ocaml/nix-overlays";
   };
 
-  outputs = { self, nixpkgs, flake-utils, nix-filter }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = nixpkgs.legacyPackages."${system}".appendOverlays [
-          (self: super: { ocamlPackages = super.ocaml-ng.ocamlPackages_5_2; })
-        ];
-
-        makeDevShell = { packages, release-mode ? false }:
-          pkgs.mkShell {
-            # dontDetectOcamlConflicts = true;
-            inputsFrom = pkgs.lib.attrValues packages;
-            nativeBuildInputs =
-              with pkgs.ocamlPackages; [ ocamlformat pkgs.nodejs_latest ]
-                ++ pkgs.lib.optionals release-mode (with pkgs; [
-                cacert
-                curl
-                ocamlPackages.dune-release
-                ocamlPackages.odoc
-                git
-              ]);
-            propagatedBuildInputs = with pkgs.ocamlPackages; [ merlin ];
-          };
-      in
-
-      rec {
-        packages = with pkgs.ocamlPackages; rec {
-          reason-react-ppx = buildDunePackage {
-            pname = "reason-react-ppx";
-            version = "n/a";
-            src = with nix-filter.lib; filter {
-              root = ./.;
-              include = [
-                "dune-project"
-                "dune"
-                "reason-react-ppx.opam"
-                "reason-react.opam"
-                "ppx"
-              ];
+  outputs = { self, nixpkgs, nix-filter }:
+    let
+      forAllSystems = f: nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed (system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system}.extend (self: super: {
+            ocamlPackages = super.ocaml-ng.ocamlPackages_5_2.overrideScope (oself: osuper: {
+              ppxlib = osuper.ppxlib.overrideAttrs (o: {
+                propagatedBuildInputs = o.propagatedBuildInputs ++ [ osuper.stdio ];
+              });
+            });
+          });
+        in
+        f pkgs);
+    in
+    {
+      packages = forAllSystems (pkgs:
+        let
+          inherit (pkgs.ocamlPackages)
+            buildDunePackage melange merlin ppxlib reason;
+          packages = rec {
+            reason-react-ppx = buildDunePackage {
+              pname = "reason-react-ppx";
+              version = "n/a";
+              src = with nix-filter.lib; filter {
+                root = ./.;
+                include = [
+                  "dune-project"
+                  "dune"
+                  "reason-react-ppx.opam"
+                  "reason-react.opam"
+                  "ppx"
+                ];
+              };
+              # Due to a Reason version mismatch, the generated OCaml PPX diff
+              # looks different
+              doCheck = false;
+              checkInputs = [ ];
+              checkPhase = "dune build @runtest -p reason-react,reason-react-ppx";
+              nativeCheckInputs = [ reason merlin pkgs.jq ];
+              propagatedBuildInputs = [ ppxlib ];
             };
-            # Due to a Reason version mismatch, the generated OCaml PPX diff
-            # looks different
-            doCheck = false;
-            checkInputs = [ ];
-            checkPhase = "dune build @runtest -p reason-react,reason-react-ppx";
-            nativeCheckInputs = [ reason merlin pkgs.jq ];
-            propagatedBuildInputs = [ ppxlib ];
-          };
 
-          reason-react = buildDunePackage {
-            pname = "reason-react";
-            version = "n/a";
-            src = with nix-filter.lib; filter {
-              root = ./.;
-              include = [
-                "dune-project"
-                "dune"
-                "reason-react-ppx.opam"
-                "reason-react.opam"
-                "src"
-                "test"
-              ];
+            reason-react = buildDunePackage {
+              pname = "reason-react";
+              version = "n/a";
+              src = with nix-filter.lib; filter {
+                root = ./.;
+                include = [
+                  "dune-project"
+                  "dune"
+                  "reason-react-ppx.opam"
+                  "reason-react.opam"
+                  "src"
+                  "test"
+                ];
+              };
+              doCheck = true;
+              nativeBuildInputs = [ melange reason ];
+              propagatedBuildInputs = [ melange reason-react-ppx ];
             };
-            doCheck = true;
-            nativeBuildInputs = [ pkgs.ocamlPackages.melange reason ];
-            propagatedBuildInputs = [
-              pkgs.ocamlPackages.melange
-              reason-react-ppx
-            ];
           };
+        in
+        packages // { default = packages.reason-react; });
 
-          default = packages.reason-react;
-        };
-
-        devShells = {
+      devShells = forAllSystems (pkgs:
+        let
+          makeDevShell = { packages, release-mode ? false }:
+            pkgs.mkShell {
+              # dontDetectOcamlConflicts = true;
+              inputsFrom = pkgs.lib.attrValues packages;
+              nativeBuildInputs =
+                with pkgs.ocamlPackages; [ ocamlformat pkgs.nodejs_latest ]
+                  ++ pkgs.lib.optionals release-mode (with pkgs; [
+                  cacert
+                  curl
+                  ocamlPackages.dune-release
+                  ocamlPackages.odoc
+                  git
+                ]);
+              propagatedBuildInputs = with pkgs.ocamlPackages; [ merlin ];
+            };
+          packages = self.packages.${pkgs.system};
+        in
+        {
           default = makeDevShell { inherit packages; };
           release = makeDevShell {
             inherit packages;
             release-mode = true;
           };
-        };
-      });
+        });
+    };
 }