add flakes

Signed-off-by: Harald Hoyer <harald@hoyer.xyz>

default.nix

@@ -0,0 +1,39 @@
+{ lib, darwin, stdenv, openssl, pkg-config, rustPlatform, }:
+let cargoFile = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package;
+in rustPlatform.buildRustPackage {
+
+  pname = cargoFile.name; # The name of the package
+  version = cargoFile.version; # The version of the package
+
+  # You can use lib here to make a more accurate source
+  # this can be nice to reduce the amount of rebuilds
+  # but thats out of scope for this post
+  src = ./.; # The source of the package
+
+  # The lock file of the package, this can be done in other ways
+  # like cargoHash, we are not doing it in this case because this
+  # is much simpler, especially if we have access to the lock file
+  # in our source tree
+  cargoLock.lockFile = ./Cargo.lock;
+
+  # The runtime dependencies of the package
+  buildInputs = [ openssl ] ++ lib.optionals stdenv.isDarwin
+    (with darwin.apple_sdk.frameworks; [
+      Security
+      CoreFoundation
+      SystemConfiguration
+    ]);
+
+  # programs and libraries used at build-time that, if they are a compiler or
+  # similar tool, produce code to run at run-time—i.e. tools used to build the new derivation
+  nativeBuildInputs = [ pkg-config ];
+
+  cargoLock.outputHashes = {
+    "mcp-core-1.0.7" = "sha256-I2lxsv71i/LLZN3r/7mwNc6nZRd1xtQNVUm/g08nhn0=";
+  };
+
+  meta = {
+    license = lib.licenses.mit;
+    mainProgram = cargoFile.name;
+  };
+}

flake.lock

@@ -0,0 +1,62 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1743315132,
+        "narHash": "sha256-6hl6L/tRnwubHcA4pfUUtk542wn2Om+D4UnDhlDW9BE=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "52faf482a3889b7619003c0daec593a1912fddc1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1736320768,
+        "narHash": "sha256-nIYdTAiKIGnFNugbomgBJR+Xv5F1ZQU+HfaBqJKroC0=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4bc9c909d9ac828a039f288cf872d16d38185db8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1743475035,
+        "narHash": "sha256-uLjVsb4Rxnp1zmFdPCDmdODd4RY6ETOeRj0IkC0ij/4=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "bee11c51c2cda3ac57c9e0149d94b86cc1b00d13",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,39 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+  };
+  outputs = { self, nixpkgs, rust-overlay, ... }:
+    let
+      namespace = "hello";
+      overlays = [ rust-overlay.overlays.default ];
+      forEachSystem = systems: f: nixpkgs.lib.genAttrs systems f;
+      forAllSystems = function:
+        nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed
+        (system: function (import nixpkgs { inherit system overlays; }));
+    in {
+      packages =
+        forAllSystems (pkgs: (self.overlays.default pkgs pkgs).${namespace});
+      cross = forAllSystems (pkgs:
+        (forEachSystem (nixpkgs.lib.filter (sys: sys != pkgs.system)
+          nixpkgs.lib.systems.flakeExposed) (crossSystem:
+            let
+              crossPkgs = import nixpkgs {
+                localSystem = pkgs.system;
+                inherit crossSystem;
+              };
+            in (self.overlays.default crossPkgs crossPkgs).${namespace})));
+      devShells =
+        forAllSystems (pkgs: (self.overlays.default pkgs pkgs).devShells);
+      formatter = forAllSystems (pkgs: pkgs.nixpkgs-fmt);
+      overlays.default = final: prev:
+        let pkgs = final;
+        in {
+          devShells.default = pkgs.callPackage ./shell.nix { };
+          ${namespace} = {
+            hello = pkgs.callPackage ./default.nix { };
+            default = pkgs.callPackage ./default.nix { };
+          };
+        };
+    };
+}

shell.nix

@@ -0,0 +1,11 @@
+{ clippy, rustfmt, callPackage, rust-analyzer, }:
+let mainPkg = callPackage ./default.nix { };
+in mainPkg.overrideAttrs (prev: {
+  nativeBuildInputs = [
+    # Additional Rust tooling
+    clippy
+    rustfmt
+    rust-analyzer
+  ] ++ (prev.nativeBuildInputs or [ ]);
+})
+