Add initial nix flake

.github/workflows/build_nix.yml

@@ -0,0 +1,13 @@
+name: "Build legacy Nix package on Ubuntu"
+
+on:
+  push:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: cachix/install-nix-action@v12
+      - name: Building package
+        run: nix-build . -A defaultPackage.x86_64-linux

default.nix

@@ -0,0 +1,7 @@
+(import (
+  fetchTarball {
+    url = "https://github.com/edolstra/flake-compat/archive/99f1c2157fba4bfe6211a321fd0ee43199025dbf.tar.gz";
+    sha256 = "0x2jn3vrawwv9xp15674wjz9pixwjyj3j771izayl962zziivbx2"; }
+) {
+  src =  ./.;
+}).defaultNix

flake.nix

@@ -0,0 +1,50 @@
+{
+  inputs = {
+    naersk.url = "github:nix-community/naersk/master";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, utils, naersk }:
+
+    utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        naersk-lib = pkgs.callPackage naersk { };
+      in
+      {
+      formatter.x86_64-linux = nixpkgs.legacyPackages.nixfmt;
+        defaultPackage = naersk-lib.buildPackage ./.;
+        devShell = with pkgs; mkShell {
+                  LIBCLANG_PATH = "${pkgs.llvmPackages.libclang}/lib/libclang.so";
+
+          nativeBuildInputs = [
+            openssl
+          ];
+
+          # necessary to override nix's defaults which cannot be overriden as others are
+          shellHook = ''
+            export CC="${pkgs.clang}/bin/clang"
+            export CXX="${pkgs.clang}/bin/clang++"
+            export LIBCLANG_PATH="${pkgs.libclang.lib}/lib"
+            rustup override set stable
+            '';
+
+          buildInputs = [
+             cargo
+             rustc
+             rustfmt
+             pre-commit
+             rustPackages.clippy
+             openssl
+             pkg-config
+             libgpg-error
+            clang
+            nettle
+            libclang
+            gpgme
+            ];
+          RUST_SRC_PATH = rustPlatform.rustLibSrc;
+        };
+      });
+}

shell.nix

@@ -0,0 +1,7 @@
+(import (
+  fetchTarball {
+    url = "https://github.com/edolstra/flake-compat/archive/99f1c2157fba4bfe6211a321fd0ee43199025dbf.tar.gz";
+    sha256 = "0x2jn3vrawwv9xp15674wjz9pixwjyj3j771izayl962zziivbx2"; }
+) {
+  src =  ./.;
+}).shellNix