[0.77] DevTools Profiler/Components doesn't initialize with JS Dev Mode off

[MorganTrudeau]

Description

I have upgraded to react-native 0.77.0 to use the new devtools which looks awesome. Unfortunately when I try to measure performance on my app with JS Dev Mode disabled the devtools profiler won't connect. Both the Profiler and Components tab will not load. Hope I'm just missing something. This wasn't working on my project so I tried with a fresh init react-native project and found the same result.

Note: This is working with JS Dev Mode enabled.

Thanks for any information!

Steps to reproduce

For me the reproduction steps are:

1. npx @react-native-community/cli@latest init AwesomeProject
2. yarn start
3. Run app on android
4. Shake device -> Settings -> Turn JS Dev Mode off
5. Hit "j" in terminal to open devtools
6. Click on Profiler

Expected Result: Profiler initializes and can be used

Actual Result: Profiler fails with error "Failed to wait for initialization: it took too long"

React Native Version

0.77.0

Output of npx react-native info

System:
  OS: macOS 14.5
  CPU: (10) x64 Apple M1 Pro
  Memory: 20.52 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 18.19.0
    path: ~/.nvm/versions/node/v18.19.0/bin/node
  Yarn:
    version: 4.3.1
    path: ~/.nvm/versions/node/v18.19.0/bin/yarn
  npm:
    version: 10.2.3
    path: ~/.nvm/versions/node/v18.19.0/bin/npm
  Watchman:
    version: 2024.12.02.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/morgantrudeau/.rvm/rubies/ruby-2.7.6/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 23.5
      - iOS 17.5
      - macOS 14.5
      - tvOS 17.5
      - visionOS 1.2
      - watchOS 10.5
  Android SDK:
    API Levels:
      - "26"
      - "27"
      - "28"
      - "29"
      - "30"
      - "31"
      - "32"
      - "33"
      - "33"
      - "33"
      - "34"
      - "35"
    Build Tools:
      - 28.0.3
      - 29.0.2
      - 29.0.3
      - 30.0.2
      - 30.0.3
      - 31.0.0
      - 33.0.0
      - 34.0.0
      - 35.0.0
    System Images:
      - android-27 | Google APIs ARM 64 v8a
      - android-31 | Google APIs ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2024.2 AI-242.23726.103.2422.12816248
  Xcode:
    version: 15.4/15F31d
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.12
    path: /usr/bin/javac
  Ruby:
    version: 2.7.6
    path: /Users/morgantrudeau/.rvm/rubies/ruby-2.7.6/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 15.0.1
    wanted: 15.0.1
  react:
    installed: 18.3.1
    wanted: 18.3.1
  react-native:
    installed: 0.77.0
    wanted: 0.77.0
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: false

Screenshots and Videos

No response

[react-native-bot]

Warning

Missing reproducer: We could not detect a reproducible example in your issue report. Please provide either:

• If your bug is UI related: a Snack
• If your bug is build/upgrade related: a project using our Reproducer Template
• Otherwise send us a Pull Request with the RNTesterPlayground.js edited to reproduce your bug.

[cortinico]

Potentially related to #49158

[huntie]

"Turn JS Dev Mode off"

Blimey, we learn about a new buried dev feature every week 🤣. Will look into this.

[MorganTrudeau]

@react-native-bot This happens in RNTesterPlayground.js with no changes and following supplied reproduction steps.

[MorganTrudeau]

Potentially related to #49158

I have run into this same heap snapshot in my own project, but this doesn't happen in a fresh project.

[huntie]

Note: This is working with JS Dev Mode enabled.

This part is critical, and this is expected behaviour. The React DevTools panels won't function if there is no development bundle running.

• We'll look at introducing an error state in the UI to make this more clear.
• Potentially, the "JS Dev Mode" toggle (implemented on Android only) should be removed.

[MorganTrudeau]

Note: This is working with JS Dev Mode enabled.

This part is critical, and this is expected behaviour. The React DevTools panels won't function if there is no development bundle running.

• We'll look at introducing an error state in the UI to make this more clear.
• Potentially, the "JS Dev Mode" toggle (implemented on Android only) should be removed.

Interesting, this link https://reactnative.dev/docs/profiling says to turn dev mode off. Is this referring to something else?

Can you advise me on how to turn development mode off and still profile? Thanks so much.