feat: use rust-overlay to get the rust binaries

This should ensure I use my own rust version instead of the one in
nixpkgs.

flake-modules/package.nix

@@ -1,16 +1,24 @@
 { inputs, ... }:
+let
+  inherit (inputs) crane;
+in
 {
   flake.overlays.default = final: prev: {
     webnsupdate = prev.callPackage ../default.nix {
-      inherit (inputs) crane;
+      inherit crane;
       pkgSrc = inputs.self;
     };
   };
 
   perSystem =
-    { pkgs, lib, ... }:
+    {
+      system,
+      pkgs,
+      lib,
+      ...
+    }:
     let
-      craneLib = inputs.crane.mkLib pkgs;
+      craneLib = (crane.mkLib pkgs).overrideToolchain (pkgs: pkgs.rust-bin.stable.latest.default);
       src = craneLib.cleanCargoSource inputs.self;
 
       commonArgs = {
@@ -36,11 +44,17 @@
         { inherit cargoArtifacts; }
       ];
       webnsupdate = pkgs.callPackage ../default.nix {
-        inherit (inputs) crane;
-        pkgSrc = inputs.self;
+        inherit crane;
+        pkgSrc = src;
       };
     in
     {
+      # Consume the rust-rust-overlay
+      _module.args.pkgs = import inputs.nixpkgs {
+        inherit system;
+        overlays = [ inputs.rust-overlay.overlays.default ];
+      };
+
       checks = {
         nextest = craneLib.cargoNextest withArtifacts;
         clippy = craneLib.cargoClippy (

flake.lock

@@ -53,10 +53,31 @@
         "crane": "crane",
         "flake-parts": "flake-parts",
         "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay",
         "systems": "systems",
         "treefmt-nix": "treefmt-nix"
       }
     },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1747363019,
+        "narHash": "sha256-N4dwkRBmpOosa4gfFkFf/LTD8oOcNkAyvZ07JvRDEf0=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "0e624f2b1972a34be1a9b35290ed18ea4b419b6f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    },
     "systems": {
       "locked": {
         "lastModified": 1681028828,

flake.nix

@@ -1,17 +1,22 @@
 {
   description = "An http server that calls nsupdate internally";
   inputs = {
-    crane.url = "github:ipetkov/crane";
+    nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz";
     flake-parts = {
       url = "github:hercules-ci/flake-parts";
       inputs.nixpkgs-lib.follows = "nixpkgs";
     };
-    nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz";
-    systems.url = "github:nix-systems/default";
     treefmt-nix = {
       url = "github:numtide/treefmt-nix";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    crane.url = "github:ipetkov/crane";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    systems.url = "github:nix-systems/default";
   };
 
   outputs =