uniwind-pro@1.1.3 crashes Hermes with "Maximum call stack size exceeded (native stack depth)" on iOS at runtime init (1.1.2 works)

[antoinerousseau]

What happened?

Bug summary

Upgrading uniwind-pro from 1.1.2 → 1.1.3 causes the app to crash immediately when the JS bundle starts evaluating on iOS / Hermes, before AppRegistry.registerComponent is reached. Pinning back to uniwind-pro@1.1.2 (no other changes) resolves the crash.

The bundle compiles successfully — the crash is at runtime during the bridgeless boot sequence:

iOS Bundled 12595ms apps/backstage/index.ts (5570 modules)
[React] [runtime not ready]: RangeError: Maximum call stack size exceeded (native stack depth)
[React] [runtime not ready]: RangeError: Maximum call stack size exceeded (native stack depth)
[React] [runtime not ready]: Invariant Violation: "main" has not been registered. This can happen if:
* Metro (the local dev server) is run from the wrong folder. Check if Metro is running, stop it and restart it in the current project.
* A module failed to load due to an error and `AppRegistry.registerComponent` wasn't called.

The "main" has not been registered line is a downstream consequence — JS evaluation aborts on the stack overflow, so expo-router/entry never registers the root component.

The error reports (native stack depth), which is Hermes' C++ runtime running out of native stack during module initialization (not a JS-level infinite loop).

Environment

uniwind-pro (broken)	1.1.3
uniwind-pro (working)	1.1.2
expo	~55.0.24
react-native	0.83.8
react	19.2.6
react-native-nitro-modules	0.35.6
react-native-reanimated	4.3.1
react-native-worklets	0.8.3
Architecture	New Architecture / Bridgeless / Hermes
Package manager	pnpm@11.1.1 (workspace monorepo, publicHoistPattern: "*")
Node	v24.15.0
macOS	26.4.1
Xcode	26.5
CocoaPods	1.16.2

metro.config.js:

const { getSentryExpoConfig } = require("@sentry/react-native/metro");
const { withUniwindConfig } = require("uniwind/metro");
const path = require("path");

const config = getSentryExpoConfig(__dirname);

config.resolver.sourceExts.push("sql");
config.resolver.blockList = [
  /\/apps\/backstage-server\/.*/,
  /\/apps\/api\/.*/,
  /\/.turbo\/.*/,
];
config.resolver.nodeModulesPaths = [
  ...config.resolver.nodeModulesPaths,
  path.resolve(__dirname, "modules"),
];
config.resolver.unstable_enablePackageExports = true;

module.exports = withUniwindConfig(config, {
  cssEntryFile: "./src/global.css",
  debug: typeof __DEV__ === "boolean" ? __DEV__ : false,
});

babel.config.js:

module.exports = function (api) {
  api.cache(true);
  return {
    presets: [["babel-preset-expo", { unstable_transformImportMeta: true }]],
    plugins: [
      ["inline-import", { extensions: [".sql"] }],
      "react-native-worklets/plugin",
    ],
  };
};

App entry (index.ts):

import "~/libs/logs";
import "~/libs/polyfills"; // @formatjs/intl-pluralrules
import "~/libs/netinfo";
import "expo-router/entry";

src/global.css:

@import "tailwindcss";
@import "uniwind";
@import "../node_modules/@shotgun/decibel/dist/themes/backstage.css";

Notes / possible angles

The 1.1.3 changelog lists changes that look adjacent to bundle / runtime initialization, particularly:

• Metro variable dependency fix — "Added missing variable metro dependency to the C++ side so CSS variable updates resolve correctly"
• Cache wipe on CSS variables update
• Deeply themed variables fix — "Fixed lookup for deeply nested themed variables"

Speculating: if the new Metro transform / C++ wiring emits a deeply nested object literal or recurses through themed variables at module init, it could plausibly blow the native Hermes stack during bundle eval.

Workaround

Pin uniwind-pro to 1.1.2:

"dependencies": {
  "uniwind": "npm:uniwind-pro@1.1.2"
}

Steps to Reproduce

In an Expo SDK 55 / RN 0.83.8 / new-arch / bridgeless app using uniwind-pro, change only the version:

- "uniwind": "npm:uniwind-pro@^1.1.2"
+ "uniwind": "npm:uniwind-pro@^1.1.3"

Then pnpm install and pnpm expo run:ios.
Steps I took to rule out cache/build artifact issues (all reproduced the crash with 1.1.3):

1. pkill Metro / dev-client processes
2. watchman watch-del-all and removed Metro / Watchman caches from $TMPDIR
3. Removed .expo, node_modules/.cache, ios/build, and Xcode DerivedData
4. expo prebuild --clean --platform ios (gitignored /ios, regenerated from scratch)
5. Fresh pod install
6. Fresh expo run:ios (full native compile from scratch, no ccache hits)
   → Same crash. Reverting only uniwind-pro to 1.1.2 (with everything else identical) fixes it.

Snack or Repository Link (Optional)

No response

Uniwind version

pro 1.1.3

React Native Version

0.83.8

Platforms

iOS

Expo

Yes

Additional information

• I've searched for similar issues in this repository and found none
• I am a Uniwind Pro user

[jpudysz]

Hey @antoinerousseau , can you try starting the dev server with the -c flag?

We haven’t received any other reports from users. We also test each release in our example apps and it works fine.

[antoinerousseau]

I retried after cleaning the workspace and rebooting my machine and the error is gone now, sorry for the noise!

[jpudysz]

No problem at all! 🙏🏼