nix: build with nix; move toolchain out of root

flake.nix

@@ -8,7 +8,11 @@
     pkgsForEach = nixpkgs.legacyPackages;
   in {
     devShells = forEachSystem (system: {
-      default = pkgsForEach.${system}.callPackage ./shell.nix {};
+      default = pkgsForEach.${system}.callPackage ./nix/shell.nix {};
+    });
+
+    packages = forEachSystem (system: {
+      default = pkgsForEach.${system}.callPackage ./nix/package.nix {};
     });
   };
 }

nix/package.nix

@@ -0,0 +1,45 @@
+{
+  lib,
+  dbus,
+  python3,
+  pkg-config,
+  rustPlatform,
+  xorg,
+  rev ? "dirty",
+}: let
+  cargoToml = builtins.fromTOML (builtins.readFile ../Cargo.toml);
+in
+  rustPlatform.buildRustPackage {
+    pname = "tailray";
+    version = "${cargoToml.package.version}-${rev}";
+
+    src = lib.fileset.toSource {
+      root = ../.;
+      fileset =
+        lib.fileset.intersection
+        (lib.fileset.fromSource (lib.sources.cleanSource ../.))
+        (lib.fileset.unions [
+          ../src
+          ../Cargo.toml
+          ../Cargo.lock
+        ]);
+    };
+
+    cargoLock.lockFile = ../Cargo.lock;
+
+    strictDeps = true;
+
+    buildInputs = [dbus xorg.libxcb];
+    nativeBuildInputs = [
+      pkg-config
+      python3
+    ];
+
+    meta = {
+      description = "Rust implementation of tailscale-systray";
+      homepage = "https://github.com/notashelf/tailray";
+      license = lib.licenses.gpl3Plus;
+      mainProgram = "tailray";
+      maintainers = with lib.maintainers; [NotAShelf];
+    };
+  }