Sentry-react-native: What are these <unknown> fatal Segfault errors with no users but many events.

[shubhamdeol]

OS:

• [ ] Windows
• [X] MacOS
• [ ] Linux

Platform:

• [ ] iOS
• [X] Android

SDK:

• [X] @sentry/react-native (>= 1.0.0)
• [ ] react-native-sentry (<= 0.43.2)

SDK version:^1.7.1

react-native version: 0.61.2

Are you using Expo?

• [ ] Yes
• [X] No

Are you using sentry.io or on-premise?

• [X] sentry.io (SaaS)
• [ ] on-premise

If you are using sentry.io, please post a link to your issue so we can take a look:

Link to issue : https://sentry.io/organizations/ekeekaran-ventures/issues/1581216965/

Configuration:

(@sentry/react-native)

Sentry.init({
  dsn: 'https://[email protected]/...'
  // other options
});

---

I have the following issue:

I am having some unknown Segfault errors, which are actually shown as fatal, also there isn't any stack trace shown. In my recent deployed app version, I have 87 events and 0 users. this looks really weird. how events are possible without users being registered to those events.

Expected result:

There should be actual users along with events and proper stack trace, which can help debug the issue.

Attaching the screenshot :

[brokestorm]

facing similar issue

[marandaneto]

@shubhamdeol thanks for raising this, can you reproduce this using an emulator or real device?

for proper symbolication, you could integrate our Gradle plugin https://docs.sentry.io/platforms/android/#gradle-integration and enable the flag uploadNativeSymbols

[shubhamdeol]

@marandaneto
We haven't been able to reproduce it. We will integrate the Gradle plugin and see if it reoccurs. I have created one more project and added sentry, made the first release on play store. That project too is having a lot of such errors, without users being registered to them.

[marandaneto]

@shubhamdeol thanks for that.

See this issue/comment: https://github.com/getsentry/sentry-android/issues/174#issuecomment-562047474

Native crashes don't have full sync. of the Scope yet, so it's not really a bug that the user is not registered, either you set the user directly on native code (if you have native code) or set it on the beforeSend callback as the comment suggest., the later might be more difficult or not possible as the RN SDK inits the Android SDK automatically under the hood.

[shubhamdeol]

@marandaneto

See this screenshot, also the error logs do not show anything about where it is coming from.

Thanks, anyway. hopefully, the integration of the Gradle plugin will help us debug this more.

[marandaneto]

@shubhamdeol thanks for sharing, do they have something in common? device brand, model or cpu arch? this is something that would be helpful to test, I can't reproduce it either.

[shubhamdeol]

@marandaneto I don't see any common device brand or modal, but I see CPU Architecture as arm64-v8a in most of them.

[marandaneto]

cc @Swatinem

[danmaas]

This looks like the JavaScriptCore crash that we are discussing here:
https://github.com/facebook/react-native/issues/25494

Basically, it's a bug deep in the JavaScript runtime environment. It's not showing as much metadata as crash reports from JavaScript code, because it takes place much deeper in the software stack.

See the issue I linked for more info and partial solutions. Some people have luck with this patched version of JSC: https://github.com/facebook/react-native/issues/25494#issuecomment-567855193 and others have better luck if they switch to the Hermes runtime. We haven't found a 100% solution yet.

[nkpatnis]

same issue, no user + crash gets reported in sentry and playstore

[ferdicus]

@shubhamdeol thanks for raising this, can you reproduce this using an emulator or real device?

for proper symbolication, you could integrate our Gradle plugin https://docs.sentry.io/platforms/android/#gradle-integration and enable the flag uploadNativeSymbols

~Hi @marandaneto, where exactly would one set uploadNativeSymbols - I couldn't find it while browsing the linked documentation, thanks in advance~

Sorry, nevermind, I found it in the proguard settings: https://docs.sentry.io/platforms/android/proguard/#gradle-configuration

Thanks 🙇🏿