feat: implement Phase 2 RNS carrier

flake.nix

@@ -4,21 +4,81 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+
+    # RNS carrier sources (upstream RNS.md sec 13): the build sandbox has no
+    # network, so every microReticulum FetchContent dependency is vendored as
+    # its own flake input and handed over via RNS_<DEP>_SOURCE_DIR.
+    # microReticulum is pinned at the commit bunshin verified against.
+    microReticulum = {
+      url = "github:attermann/microReticulum/40fa628809d57140180c1c833559ab96fec992c1";
+      flake = false;
+    };
+    rns-arduinojson = {
+      url = "github:bblanchon/ArduinoJson/ed69feadb95182dc53ac978975d310122060a767";
+      flake = false;
+    };
+    rns-msgpack = {
+      url = "github:hideakitai/MsgPack/1f552c31b940d6e9063ee17a4b3fa10c47b27169";
+      flake = false;
+    };
+    rns-arxcontainer = {
+      url = "github:hideakitai/ArxContainer/d6affcd0bc83219b863c20abf7c269214db8db2a";
+      flake = false;
+    };
+    rns-arxtypetraits = {
+      url = "github:hideakitai/ArxTypeTraits/702de9cc59c7e047cdc169ae3547718b289d2c02";
+      flake = false;
+    };
+    rns-debuglog = {
+      url = "github:hideakitai/DebugLog/b581f7dde6c276c5df684e2328f406d9754d2f46";
+      flake = false;
+    };
+    rns-crypto = {
+      url = "github:attermann/Crypto/984dc891330986c302a86c4e312d4f5abcc28359";
+      flake = false;
+    };
+    rns-microstore = {
+      url = "github:attermann/microStore/0f28567fe00ab8ab14624a34c2e9e0a000a44c46";
+      flake = false;
+    };
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, nixpkgs, flake-utils, microReticulum, rns-arduinojson
+            , rns-msgpack, rns-arxcontainer, rns-arxtypetraits, rns-debuglog
+            , rns-crypto, rns-microstore }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs { inherit system; };
+        inherit (pkgs) lib;
+
+        # build.rs consumes these directly; with every dependency vendored,
+        # the cmake configure step never fetches.
+        rnsSourceEnv = {
+          MICRORETICULUM_SOURCE_DIR = "${microReticulum}";
+          RNS_ARDUINOJSON_SOURCE_DIR = "${rns-arduinojson}";
+          RNS_MSGPACK_SOURCE_DIR = "${rns-msgpack}";
+          RNS_ARXCONTAINER_SOURCE_DIR = "${rns-arxcontainer}";
+          RNS_ARXTYPETRAITS_SOURCE_DIR = "${rns-arxtypetraits}";
+          RNS_DEBUGLOG_SOURCE_DIR = "${rns-debuglog}";
+          RNS_CRYPTO_SOURCE_DIR = "${rns-crypto}";
+          RNS_MICROSTORE_SOURCE_DIR = "${rns-microstore}";
+        };
+
         fumi = { rns ? false }: pkgs.rustPlatform.buildRustPackage {
           pname = "fumi";
           version = "0.1.0";
           src = ./.;
           cargoLock.lockFile = ./Cargo.lock;
-          buildFeatures = pkgs.lib.optionals rns [ "rns" ];
-          # The rns feature vendors microReticulum behind the shim and needs
-          # MICRORETICULUM_SOURCE_DIR; it is added with the RNS carrier.
-          doCheck = !rns;
+          nativeBuildInputs = [ pkgs.pkg-config ]
+            ++ lib.optionals rns [ pkgs.cmake pkgs.ninja pkgs.gcc ];
+          buildFeatures = lib.optionals rns [ "rns" ];
+          env = lib.optionalAttrs rns rnsSourceEnv;
+          # ninja's setup hook claims buildPhase before the cargo hooks
+          # can, which would run ninja against no build.ninja instead of
+          # cargo; ninja here is only for build.rs to invoke through cmake.
+          dontUseNinjaBuild = rns;
+          dontUseNinjaCheck = rns;
+          dontUseNinjaInstall = rns;
         };
       in
       {
@@ -31,7 +91,18 @@
         };
 
         devShells.default = pkgs.mkShell {
-          packages = with pkgs; [ cargo rustc rustfmt clippy sqlite ];
+          packages = with pkgs; [
+            cargo
+            rustc
+            rustfmt
+            clippy
+            pkg-config
+            sqlite
+            cmake
+            ninja
+            gcc
+          ];
+          env = rnsSourceEnv;
         };
       });
 }