newArchEnabled=true not working on android

[Yoon-SeungHwan]

Description

I'm trying integration RN onto existing android app based on guide

after finish every steps, I did set newArchEnabled=true in gradle.properties

however it looks not working when the app access to metro bundle I can see

Running "MyAppName" with {"rootTag":11}

without the flag. fabric: true

Steps to reproduce

1. create RN project
2. paste existing android project under RN project
3. set newArchEnabled=true
4. build and run on device

React Native Version

0.74.1

Affected Platforms

Runtime - Android

Areas

Fabric - The New Renderer, Codegen

Output of npx react-native info

System:
  OS: macOS 13.6
  CPU: (10) arm64 Apple M1 Pro
  Memory: 79.95 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.12.0
    path: ~/.nvm/versions/node/v20.12.0/bin/node
  Yarn:
    version: 3.6.4
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.5.0
    path: ~/.nvm/versions/node/v20.12.0/bin/npm
  Watchman:
    version: 2024.05.06.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.14.3
    path: /Users/dylan/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 23.2
      - iOS 17.2
      - macOS 14.2
      - tvOS 17.2
      - visionOS 1.0
      - watchOS 10.2
  Android SDK:
    API Levels:
      - "28"
      - "32"
      - "33"
      - "34"
    Build Tools:
      - 28.0.3
      - 30.0.3
      - 32.0.0
      - 33.0.0
      - 33.0.1
      - 34.0.0
    System Images:
      - android-33 | Google APIs ARM 64 v8a
    Android NDK: 22.1.7171670
IDEs:
  Android Studio: 2023.2 AI-232.10300.40.2321.11567975
  Xcode:
    version: 15.2/15C500b
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.11
    path: /Users/dylan/.jenv/shims/javac
  Ruby:
    version: 3.3.0
    path: /Users/dylan/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 18.2.0
    wanted: 18.2.0
  react-native:
    installed: 0.74.1
    wanted: 0.74.1
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: false

Stacktrace or Logs

nothing

Reproducer

nothing

Screenshots and Videos

No response

[cortinico]

We can't help you further without any more information. We'll need to see the code somehow of your application

[Yoon-SeungHwan]

We can't help you further without any more information. We'll need to see the code somehow of your application

I put repository url for reproducer @cortinico

what i did is, create react-native project, create new android to replacement android inside of RN project follow https://reactnative.dev/docs/integration-with-existing-apps?language=kotlin and add below properties into gradle.properties

hermesEnabled=true
newArchEnabled=true

[cortinico]

So your setup can't work as it is. You're missing the MainApplication class which is needed to initialize everything properly.

Please take a look at the official template and update your setup to match the one from the template:

https://github.com/facebook/react-native/tree/0.74-stable/packages/react-native/template/android/app/src/main/java/com/helloworld