Update flake.nix

flake.nix

@@ -1,56 +1,42 @@
 {
   description = "A massively parallel functional runtime.";
+
   inputs = {
-    flake-compat = {
-      flake = false;
-      url = "github:edolstra/flake-compat";
-    };
-    nci = {
-      inputs.nixpkgs.follows = "nixpkgs";
-      url = "github:yusdacra/nix-cargo-integration";
-    };
-    nix-filter.url = "github:numtide/nix-filter";
-    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay.url = "github:oxalica/rust-overlay";
   };
-  outputs = inputs:
-    let
-      name = "hvm";
-      nix-filter = import inputs.nix-filter;
-      pkgs = common: packages:
-        builtins.map (element: common.pkgs.${element}) packages;
-    in inputs.nci.lib.makeOutputs {
-      config = common: {
-        cCompiler = { package = common.pkgs.clang; };
-        outputs = {
-          defaults = {
-            app = name;
-            package = name;
-          };
-        };
-        runtimeLibs = pkgs common [ "openssl" ];
-        shell = {
-          commands =
-            builtins.map (element: { package = common.pkgs.${element}; }) [
-              "ghc"
-              "nodejs"
-            ];
+
+  outputs = { self, nixpkgs, flake-utils, rust-overlay }: 
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ rust-overlay.overlay ];
         };
-      };
-      pkgConfig = common:
-        let
-          override = { buildInputs = pkgs common [ "openssl" "pkg-config" ]; };
-        in {
-          ${name} = {
-            app = true;
-            build = true;
-            depsOverrides = { inherit override; };
-            overrides = { inherit override; };
-            profiles = { release = false; };
+
+        src = builtins.filterSource
+          (name: type: builtins.elem (baseNameOf name) [
+            "src" "Cargo.lock" "Cargo.toml" "rust-toolchain.toml"
+          ])
+          ./.;
+
+      in {
+        packages = {
+          hvm = pkgs.stdenv.mkDerivation {
+            pname = "hvm";
+            version = "0.1.0";
+            src = pkgs.lib.cleanSource src;
+            buildInputs = [ pkgs.rustPlatform.rust ];
+            buildPhase = "cargo build --release";
+            installPhase = ''
+              mkdir -p $out/bin
+              cp target/release/hvm $out/bin/
+            '';
           };
         };
-      root = nix-filter {
-        root = ./.;
-        include = [ "src" "Cargo.lock" "Cargo.toml" "rust-toolchain.toml" ];
-      };
-    };
+
+        defaultPackage = self.packages.${system}.hvm;
+      }
+    );
 }