Add nix env

.envrc

@@ -0,0 +1 @@
+use nix

shell.nix

@@ -0,0 +1,17 @@
+let
+  mozilla = import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz);
+  pkgs = import <nixpkgs> { overlays = [ mozilla ]; };
+  rustChannel = pkgs.latest.rustChannels.stable;
+in
+
+with pkgs;
+
+mkShell {
+  buildInputs = [
+    rustChannel.rust
+  ];
+
+  shellHook = ''
+    export RUST_SRC_PATH="${rustChannel.rust-src}/lib/rustlib/src/rust/library"
+  '';
+}