flake.nix

{
  description = "A devShell example";

  inputs = {
    nixpkgs.url      = "github:NixOS/nixpkgs/nixos-unstable";
    rust-overlay.url = "github:oxalica/rust-overlay";
    rust-overlay.inputs.nixpkgs.follows = "nixpkgs";
    flake-utils.url  = "github:numtide/flake-utils";
    flake-utils.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        overlays = [ (import rust-overlay) ];
        pkgs = import nixpkgs {
          inherit system overlays;
        };
        rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
      in
      {
        devShells.default = pkgs.mkShell {
          nativeBuildInputs = [
            rustToolchain
          ];
        };
      }
    );
}