Simplify nixpkgs workaround (#84)

- Apply that overlay only on macOS
- Make use of the overlay system
- Update nixpkgs and haskell-flake

flake.lock

@@ -35,11 +35,11 @@
     },
     "haskell-flake": {
       "locked": {
-        "lastModified": 1674483307,
-        "narHash": "sha256-NlohHWCqOsMY4q2fmKR6VAAX4y09Cr85Ezgbx4Q2hbc=",
+        "lastModified": 1675623979,
+        "narHash": "sha256-eD01oAbmfWhAVHesQrsZkGdueV7xtV1AmhGDEvJV2XA=",
         "owner": "srid",
         "repo": "haskell-flake",
-        "rev": "8688fb2deaa193795467eedb4d2473dbeaba19b4",
+        "rev": "014aa621ec2e910766f8fbe03dc9638984a359eb",
         "type": "github"
       },
       "original": {
@@ -102,11 +102,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1674361931,
-        "narHash": "sha256-lUIZItHbW+LmJAz9V9puLq2rHlewcUgg1RPehkQIkzc=",
+        "lastModified": 1675584158,
+        "narHash": "sha256-SBkchaDzCHxnPNRDdtZ5ko5caHio9iS0Mbyn/xXbXxs=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "ef479383e13698c8d5ccf8a608485dc8ce1d4f80",
+        "rev": "d840126a0890621e7b220894d749132dd4bde6a0",
         "type": "github"
       },
       "original": {

flake.nix

@@ -18,32 +18,41 @@
         inputs.flake-root.flakeModule
         inputs.mission-control.flakeModule
       ];
-      perSystem = { self', lib, config, pkgs, ... }: {
+      perSystem = { self', system, lib, config, pkgs, ... }: {
         # The "main" project. You can have multiple projects, but this template
         # has only one.
         haskellProjects.main = {
           packages = {
             haskell-template.root = ./.;
           };
-          buildTools = hp:
+          overrides =
             let
               # Workaround for https://github.com/NixOS/nixpkgs/issues/140774
-              fixCyclicReference = drv:
-                pkgs.haskell.lib.overrideCabal drv (_: {
-                  enableSeparateBinOutput = false;
-                });
+              nixpkgsWorkaround =
+                let
+                  disableSeparateBinOutput =
+                    pkgs.haskell.lib.compose.overrideCabal (_: { enableSeparateBinOutput = false; });
                 in
-            {
+                self: super: lib.optionalAttrs (system == "aarch64-darwin") {
+                  ghcid = disableSeparateBinOutput super.ghcid;
+                  ormolu = disableSeparateBinOutput super.ormolu;
+                };
+              projectOverrides = self: super: {
+                # Add your own overrides here.
+              };
+            in
+            lib.composeManyExtensions [
+              nixpkgsWorkaround
+              projectOverrides
+            ];
+          devShell = {
+            tools = hp: {
               treefmt = config.treefmt.build.wrapper;
-              ghcid = fixCyclicReference hp.ghcid;
-              haskell-language-server = hp.haskell-language-server.overrideScope (lself: lsuper: {
-                ormolu = fixCyclicReference hp.ormolu;
-              });
             } // config.treefmt.build.programs;
-          # overrides = self: super: with pkgs.haskell.lib; {};
             hlsCheck.enable = false;
             hlintCheck.enable = true;
           };
+        };
 
         # Auto formatters. This also adds a flake check to ensure that the
         # source tree was auto formatted.