chore: Update nix flake for development shell

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1,2 +1,2 @@
 /target
-.envrc
+.direnv

flake.lock

@@ -1,28 +1,30 @@
 {
   "nodes": {
-    "nixpkgs": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
       "locked": {
-        "lastModified": 1724395761,
+        "lastModified": 1731533236,
-        "narHash": "sha256-zRkDV/nbrnp3Y8oCADf5ETl1sDrdmAW6/bBVJ8EbIdQ=",
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "NixOS",
+        "owner": "numtide",
-        "repo": "nixpkgs",
+        "repo": "flake-utils",
-        "rev": "ae815cee91b417be55d43781eb4b73ae1ecc396c",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
+        "owner": "numtide",
-        "ref": "nixpkgs-unstable",
+        "repo": "flake-utils",
-        "repo": "nixpkgs",
         "type": "github"
       }
     },
-    "nixpkgs_2": {
+    "nixpkgs": {
       "locked": {
-        "lastModified": 1718428119,
+        "lastModified": 1731890469,
-        "narHash": "sha256-WdWDpNaq6u1IPtxtYHHWpl5BmabtpmLnMAx0RdJ/vo8=",
+        "narHash": "sha256-D1FNZ70NmQEwNxpSSdTXCSklBH1z2isPR84J6DQrJGs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "e6cea36f83499eb4e9cd184c8a8e823296b50ad5",
+        "rev": "5083ec887760adfe12af64830a66807423a859a7",
         "type": "github"
       },
       "original": {
@@ -34,20 +36,23 @@
     },
     "root": {
       "inputs": {
+        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs",
         "rust-overlay": "rust-overlay"
       }
     },
     "rust-overlay": {
       "inputs": {
-        "nixpkgs": "nixpkgs_2"
+        "nixpkgs": [
+          "nixpkgs"
+        ]
       },
       "locked": {
-        "lastModified": 1724638882,
+        "lastModified": 1732242723,
-        "narHash": "sha256-ap2jIQi/FuUHR6HCht6ASWhoz8EiB99XmI8Esot38VE=",
+        "narHash": "sha256-NWI8csIK0ujFlFuEXKnoc+7hWoCiEtINK9r48LUUMeU=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "19b70f147b9c67a759e35824b241f1ed92e46694",
+        "rev": "a229311fcb45b88a95fdfa5cecd8349c809a272a",
         "type": "github"
       },
       "original": {
@@ -55,6 +60,21 @@
         "repo": "rust-overlay",
         "type": "github"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -3,36 +3,36 @@
 
     inputs = {
         nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
-        rust-overlay.url = "github:oxalica/rust-overlay";
+        flake-utils = {
+            url = "github:numtide/flake-utils";
+            inputs.nixpkgs.follows = "nixpkgs";
+        };
+        rust-overlay = {
+            url = "github:oxalica/rust-overlay";
+            inputs.nixpkgs.follows = "nixpkgs";
+        };
     };
 
-    outputs = { nixpkgs, rust-overlay, ... }:
+    outputs = { nixpkgs, flake-utils, rust-overlay, ... }:
-    let
+        flake-utils.lib.eachDefaultSystem (system:
-        system = "x86_64-linux";
+            let
+                overlays = [ (import rust-overlay) ];
+                pkgs = import nixpkgs { inherit system overlays; };
 
-        pkgs = import nixpkgs {
+                rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
-            inherit system;
+                rustNightlyToolchain = pkgs.rust-bin.selectLatestNightlyWith (t: t.minimal.override {
-            overlays = [ (import rust-overlay) ];
+                    extensions = [ "rustfmt" ];
-        };
+                });
 
-        rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+                buildTools = [
+                    rustToolchain
+                    rustNightlyToolchain
+                ];
+            in {
+                devShells.default = pkgs.mkShell {
+                    name = "projtool";
 
-        # For unstable rustfmt features
+                    nativeBuildInputs = buildTools;
-        rustNightlyToolchain = pkgs.rust-bin.selectLatestNightlyWith (toolchain: toolchain.minimal.override {
+                };
-            extensions = [ "rustfmt" ];
+            });
-        });
-
-        buildTools = with pkgs; [
-            rustToolchain
-            rustNightlyToolchain
-            pkg-config
-        ];
-
-        devShell = pkgs.mkShell {
-            name = "projtool";
-            buildInputs = buildTools;
-        };
-    in {
-        devShells.${system}.default = devShell;
-    };
 }