Add nix files

default.nix

@@ -0,0 +1,52 @@
+let
+  rustOverlay = import (
+    builtins.fetchTarball {
+      url = "https://github.com/oxalica/rust-overlay/archive/master.tar.gz";
+      sha256 = "0qgrkgc695a7gja83dngxrcx4gdg9056gvg5325i5yyjxg0ni6c9";
+    }
+  );
+  pkgsDefault = import <nixpkgs> { overlays = [ rustOverlay ]; };
+  rustToolchain = pkgsDefault.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+  rustPlatformDefault = pkgsDefault.makeRustPlatform {
+    cargo = rustToolchain;
+    rustc = rustToolchain;
+  };
+in
+{
+  pkgs ? pkgsDefault,
+  pileRustPlatform ? rustPlatformDefault,
+}:
+
+pileRustPlatform.buildRustPackage {
+  pname = "pile";
+  version = "0.0.1";
+  src = ./.;
+
+  cargoLock.lockFile = ./Cargo.lock;
+
+  PDFIUM_LIB_DIR = "${pkgs.pdfium-binaries}/lib";
+
+  buildInputs = [
+    pkgs.pdfium-binaries
+    pkgs.openssl
+  ]
+  ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
+    pkgs.darwin.apple_sdk.frameworks.Security
+    pkgs.darwin.apple_sdk.frameworks.SystemConfiguration
+  ];
+
+  nativeBuildInputs = [
+    pkgs.pkg-config
+    pkgs.makeWrapper
+  ];
+
+  postInstall = ''
+    wrapProgram $out/bin/pile \
+      --prefix LD_LIBRARY_PATH : ${pkgs.lib.makeLibraryPath [ pkgs.pdfium-binaries ]}
+  '';
+
+  meta = {
+    description = "pile - flexible file indexing";
+    mainProgram = "pile";
+  };
+}