feat: add flake compat

Signed-off-by: Brian McGee <brian@bmcgee.ie>

default.nix

@@ -0,0 +1,17 @@
+# This file provides backward compatibility to nix < 2.4 clients
+{system ? builtins.currentSystem}: let
+  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+
+  inherit (lock.nodes.flake-compat.locked) owner repo rev narHash;
+
+  flake-compat = fetchTarball {
+    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz";
+    sha256 = narHash;
+  };
+
+  flake = import flake-compat {
+    inherit system;
+    src = ./.;
+  };
+in
+  flake.defaultNix

flake.lock

@@ -21,6 +21,21 @@
         "type": "github"
       }
     },
+    "flake-compat": {
+      "locked": {
+        "lastModified": 1688025799,
+        "narHash": "sha256-ktpB4dRtnksm9F5WawoIkEneh1nrEvuxb5lJFt1iOyw=",
+        "owner": "nix-community",
+        "repo": "flake-compat",
+        "rev": "8bf105319d44f6b9f0d764efa4fdef9f1cc9ba1c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib"
@@ -163,6 +178,7 @@
     "root": {
       "inputs": {
         "devshell": "devshell",
+        "flake-compat": "flake-compat",
         "flake-parts": "flake-parts",
         "flake-root": "flake-root",
         "gomod2nix": "gomod2nix",

flake.nix

@@ -3,7 +3,6 @@
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
-
     flake-parts.url = "github:hercules-ci/flake-parts";
     flake-root.url = "github:srid/flake-root";
     treefmt-nix = {
@@ -19,8 +18,8 @@
       url = "github:nix-community/gomod2nix";
       inputs.nixpkgs.follows = "nixpkgs";
     };
-
     nix-filter.url = "github:numtide/nix-filter";
+    flake-compat.url = "github:nix-community/flake-compat";
   };
 
   outputs = inputs @ {flake-parts, ...}:

shell.nix

@@ -0,0 +1,17 @@
+# This file provides backward compatibility to nix < 2.4 clients
+{system ? builtins.currentSystem}: let
+  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+
+  inherit (lock.nodes.flake-compat.locked) owner repo rev narHash;
+
+  flake-compat = fetchTarball {
+    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz";
+    sha256 = narHash;
+  };
+
+  flake = import flake-compat {
+    inherit system;
+    src = ./.;
+  };
+in
+  flake.shellNix