Add nix flake

Author: volhovm

flake.lock

@@ -0,0 +1,39 @@
+{
+  description = "openmina prerequisites";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, utils }:
+    utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+      in
+      {
+        devShell = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            rustup
+            rust-analyzer
+            libiconv # Needed for macOS for rustup
+
+            openssl
+            jemalloc
+            protobuf
+            libpcap
+
+            pkg-config
+            gcc
+            gnumake
+          ];
+
+          # Fix for tikv-jemalloc-sys compilation error on GNU platforms:
+          # The GNU version of strerror_r returns char* while POSIX returns int.
+          # Only set this flag on Linux/GNU systems, not needed on macOS.
+          CFLAGS = if pkgs.stdenv.isLinux then "-DJEMALLOC_STRERROR_R_RETURNS_CHAR_WITH_GNU_SOURCE" else "";
+          JEMALLOC_SYS_WITH_CFLAGS = if pkgs.stdenv.isLinux then "-DJEMALLOC_STRERROR_R_RETURNS_CHAR_WITH_GNU_SOURCE" else "";
+        };
+      }
+    );
+}