add smfh as a package for stable users

default.nix

@@ -193,6 +193,7 @@ in
             after = [ "arbys-prep.service" ];
             script =
               let
+                linker = lib.getExe (pkgs.smfh or (pkgs.rustPlatform.buildRustPackage ./smfh.nix { }));
               in
               ''
                 new_manifest=${manifest}

smfh.nix

@@ -0,0 +1,20 @@
+{
+  rustPlatform,
+  fetchFromGitHub,
+}:
+let
+  src = fetchFromGitHub {
+    owner = "feel-co";
+    repo = "smfh";
+    rev = "39f5c06153f63100376bc607b1465850b6df77fd";
+    hash = "sha256-/9Ww10kYopxfCNNnNDwENTubs7Wzqlw+O6PJAHNOYQw=";
+  };
+  cargo = (builtins.fromTOML (builtins.readFile "${src}/Cargo.toml"));
+in
+rustPlatform.buildRustPackage {
+  inherit src;
+  inherit (cargo.package) version;
+  pname = cargo.package.name;
+  cargoLock.lockFile = "${src}/Cargo.lock";
+  meta.mainProgram = "smfh";
+}