Add a flake for rust-avr

.gitignore

@@ -1,2 +1,4 @@
 Cargo.lock
 target/
+.envrc
+.direnv

flake.lock

@@ -0,0 +1,93 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1667077288,
+        "narHash": "sha256-bdC8sFNDpT0HK74u9fUkpbf1MEzVYJ+ka7NXCdgBoaA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "6ee9ebb6b1ee695d2cacc4faa053a7b9baa76817",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "locked": {
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1666961615,
+        "narHash": "sha256-+Sqz6zQA85Q14U/KwsJO386oxd47zDte8dqBGOtRJGg=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "040c6d8374d090f46ab0e99f1f7c27a4529ecffd",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-22.05",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1665296151,
+        "narHash": "sha256-uOB0oxqxN9K7XGF1hcnY+PQnlQJ+3bP2vCn/+Ru/bbc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "14ccaaedd95a488dd7ae142757884d8e125b3363",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1667098607,
+        "narHash": "sha256-zTYgUaS+81mNq8Z0v2WYr46ACJFBeWqcQfOVQaTxtNE=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "de5c4d5d40ae0a0dab67c5f7ae8d26c5445cf00d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,34 @@
+{
+  description = "Rust Spellbook";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-22.05";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
+  flake-utils.lib.eachDefaultSystem (system:
+      let
+        version = builtins.string 0 8 self.lastModifiedDate;
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+        rust = pkgs.rust-bin.nightly.latest.default.override {
+          extensions = [ "rust-src" ];
+        };
+        avr = pkgs.pkgsCross.avr.buildPackages;
+      in {
+
+        devShells.default = pkgs.mkShell {
+          name = "rust-avr";
+          buildInputs = [
+            avr.gcc
+            avr.avrdude
+            rust
+          ];
+        };
+      }
+    );
+}