Version 8.x.x with Capture App Start Errors enabled - duplicate JS issue reporting

[gkartalis]

What React Native libraries do you use?

RN New Architecture, React Navigation, Hermes

Are you using sentry.io or on-premise?

sentry.io (SaS)

Are you using any other error monitoring solution alongside Sentry?

No

Other Error Monitoring Solution Name

No response

@sentry/react-native SDK Version

8.10.0

How does your development environment look like?

System:
  OS: macOS 26.3.1
  CPU: (12) arm64 Apple M2 Pro
  Memory: 111.80 MB / 32.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 24.6.0
    path: ~/.local/share/mise/installs/node/24.6.0/bin/node
  Yarn:
    version: 4.10.3
    path: ~/.local/share/mise/installs/yarn/4.10.3/bin/yarn
  npm:
    version: 11.5.1
    path: ~/.local/share/mise/installs/node/24.6.0/bin/npm
  Watchman:
    version: 2026.01.12.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /Users/georgioskartalis/.local/share/mise/installs/ruby/3.1.7/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.2
      - iOS 26.2
      - macOS 26.2
      - tvOS 26.2
      - visionOS 26.2
      - watchOS 26.2
  Android SDK:
    API Levels:
      - "30"
      - "31"
      - "34"
      - "35"
      - "36"
    Build Tools:
      - 33.0.1
      - 34.0.0
      - 35.0.0
      - 36.0.0
      - 36.1.0
    System Images:
      - android-30 | Google APIs ARM 64 v8a
      - android-34 | Google Play ARM 64 v8a
      - android-35 | Google Play ARM 64 v8a
      - android-35 | Pre-Release 16 KB Page Size Google Play ARM 64 v8a
      - android-35 | Google Play Tablet ARM 64 v8a
      - android-36.1 | Pre-Release 16 KB Page Size Google Play ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2025.2 AI-252.28238.7.2523.14688667
  Xcode:
    version: 26.2/17C52
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.11
    path: /Users/georgioskartalis/.local/share/mise/installs/java/zulu-17.50.19.0/bin/javac
  Ruby:
    version: 3.1.7
    path: /Users/georgioskartalis/.local/share/mise/installs/ruby/3.1.7/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.0
    wanted: 20.0.0
  react:
    installed: 19.1.0
    wanted: 19.1.0
  react-native:
    installed: 0.81.5
    wanted: patch:react-native@npm%3A0.81.5#~/.yarn/patches/react-native-npm-0.81.5-d8232ef145.patch
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Sentry.init()

sentry.options.json:

{
"dsn": "sentryDSN",
"release": "releaseName",
"dist": "dist"
}

Sentry.init({
dsn: sentryDSN,
release: eigenSentryReleaseName(),
dist: eigenSentryDist(),
enableTombstone: true,
enableAutoSessionTracking: true,
enableWatchdogTerminationTracking: false,
attachStacktrace: true,
tracesSampleRate: props.debug ? 1.0 : 0.05,
profilesSampleRate: props.debug ? 1.0 : 0.05,
debug: props.debug,
integrations: [navigationInstrumentation],
...props,
})

Steps to Reproduce

Steps to Reproduce:

PR where we are working on this: artsy/eigen#13505

The repro steps are basically triggering a manual JS crash on iOS :

       <DevMenuButtonItem
            title="Throw Sentry Error"
            onPress={() => {
              if (!Keys.secureFor("SENTRY_DSN")) {
                Alert.alert(
                  "No Sentry DSN available",
                  __DEV__ ? "Set it in keys.shared.json and re-build the app." : undefined
                )
                return
              }
              throw Error("Sentry test error")
            }}
          />

Expected Result

We would expect (as it was on previous versions) to get one single JS report for each issue.

Actual Result

We are getting most of the times two reports one C++ and one JS

Tried also autoInitializeNativeSdk: false because it wasn't clear to me if we need to do this in order to have Capture App Start errors working properly with or without it from the docs.

Release with autoInitializeNativeSdk: false here

Release without autoInitializeNativeSdk: false here

It also reminded me of this issue that I opened a while ago and it was fixed in 7.9.0 but this time we are not getting duplicates for all the manually triggered JS errors but only for some of them.

[linear-code]

RN-619

[alwx]

Thanks for reporting, @gkartalis. We've seen your request and added it to our queue.

We'll review it shortly and follow up if we need more information or once next steps are clearer.