add nix flake

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1707743206,
+        "narHash": "sha256-AehgH64b28yKobC/DAWYZWkJBxL/vP83vkY+ag2Hhy4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2d627a2a704708673e56346fcb13d25344b8eaf3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,34 @@
+{
+  description = "simple command line mail client";
+
+  inputs = {
+    nixpkgs.url = github:NixOS/nixpkgs/nixpkgs-unstable;
+  };
+
+  outputs = { self, nixpkgs }:
+  with nixpkgs.lib;
+  let
+    forAllSystems = fn:
+      genAttrs platforms.unix (system:
+        fn (import nixpkgs {
+          inherit system;
+        })
+      );
+  in
+  {
+    packages = forAllSystems (pkgs: {
+      default = pkgs.stdenv.mkDerivation (with pkgs; {
+        name = "mal";
+        src = ./.;
+
+        nativeBuildInputs = [ ldc ];
+        buildInputs = [ curl ];
+
+        installFlags = [
+          "DESTDIR=$(out)"
+          "PREFIX=/"
+        ];
+      });
+    });
+  };
+}