TypeError: global.nativeTraceBeginSection is not a function (Systrace)

Is this a bug report?

Yes

Have you read the Bugs section of the Contributing to React Native Guide?

Yes

Environment

1. react-native -v: react-native-cli: 2.0.1, react-native: 0.46.1
2. node -v: v7.10.0
3. npm -v: 4.6.1
4. yarn --version (if you use Yarn): Not used in this bug

Then, specify:

• Target Platform: iOS

• Development Operating System: macOS Sierra v 10.12

• Build tools: Xcode Version 8.3.3 (8E3004b)

I’m running react-native run-ios deploying to iOS emulator Version 10.0 (SimulatorApp-745.10), running iOS 10.3 in an iphone 6.

Steps to Reproduce

(Write your steps here:)

1. Run react-native run-ios with Systrace enabled

1. Reload your app (manually or with live/hot reload)

2. Check the logs

Expected Behavior

The app should reload normally.

Actual Behavior

The error TypeError:global.nativeTraceBeginSection gets launched into the console:

And in the UI:

After that, the whole emulator crashes and the only way to restore it is running react-native run-ios again. One temporary workaround to get rid of this error is disabling Systrace in the DevMenu, but this is less than ideal.

Reproducible Demo

https://snack.expo.io/ryCtYZHrZ

Observation: Even though I included a snack, I’m afraid you can’t fully reproduce this problem without a Mac and an iOS emulator, the reason being that the Systrace is not an Expo function.

[GuoZhiQiang]

Following steps help me:

• Press Cmd+D (or shake the device )to show the Dev menu.
• Select Stop Systrace option.
• Restart the app.

[gaearon]

I’ve brought it up internally, and there’s a person who planned to look into fixing this either in December on January. If it’s not fixed by the end of January please ping me in person (e.g. on Twitter DM) and I’ll try to see what’s the status on this.