Add initial flake.nix; just for develop, for now (fixes#3577)

.envrc

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

.gitignore

@@ -1,3 +1,4 @@
+.direnv/
 /target/
 **/*.rs.bk
 
@@ -12,3 +13,5 @@
 /assets/completions/bat.zsh
 /assets/manual/bat.1
 /assets/metadata.yaml
+
+

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1769789167,
+        "narHash": "sha256-kKB3bqYJU5nzYeIROI82Ef9VtTbu4uA3YydSk/Bioa8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "62c8382960464ceb98ea593cb8321a2cf8f9e3e5",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,40 @@
+{
+  description = "bat";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs =
+    { self, ... }@inputs:
+    let
+      supportedSystems = [
+        "x86_64-linux" # 64-bit Intel/AMD Linux
+        "aarch64-linux" # 64-bit ARM Linux
+        "aarch64-darwin" # 64-bit ARM macOS
+      ];
+
+      forEachSupportedSystem =
+        f:
+        inputs.nixpkgs.lib.genAttrs supportedSystems (
+          system:
+          f {
+            inherit system;
+            pkgs = import inputs.nixpkgs {
+              inherit system;
+              config.allowUnfree = true;
+            };
+          }
+        );
+    in
+    {
+      devShells = forEachSupportedSystem (
+        { pkgs, system }:
+        {
+          default = pkgs.mkShellNoCC {
+            packages = with pkgs; [
+              cargo
+            ];
+          };
+        }
+      );
+    };
+}