Freeze & Crash when remote debug enabled RN@0.42.0-rc.1

Description

I tried to update an existing project to RN@0.42.0-rc.1 and noticed that the app freezes and crashes when I try to dispatch a redux action open a modal. I then went and tried to isolate the issue and found out it crashes only when remote debug is enabled, which makes me think it might not be related to redux. This is the last error in console:

Error: Attempted to remove more RCTKeyboardObserver listeners than added

Reproduction

1. clone and install patrikholcak/react-native-remote-bug
2. Run iOS simulator, toggle remote debug on
3. Click Toggle modal — first click will freeze the app and the second one will crash it

Solution

No idea.

Additional Information

• React Native version: 0.42.0-rc.1
• Platform: iOS
• Operating System: MacOS

[cailenmusselman]

Oooookay guys, so I have it figured out… sort of.

The elevation changes I introduced to YellowBox cause iOS apps to hang when remote debugging is enabled and a warning is logged.

So my changes do not effect the Modal component directly, it’s just that Modal is logging the warning "Calling of '[-RCTUIManager setFrame:forView]' which is deprecated" which in turn brings out the bug introduced by my YellowBox changes in iOS.

So the actual bug we’re observing is what @alphasp posted.

In summary: Android + no remote debugging = OK Android + remote debugging = OK iOS + no remote debugging = OK iOS + remote debugging = HANGS

Interestingly, if I change elevation: Number.MAX_VALUE to Number.MAX_SAFE_INTEGER the bug dissappears. So maybe there’s some sort of overflow occurring on iOS, I’m not sure.

I don’t really have the time to get to the actual root of the issue, so I just propose any of these changes:

elevation: Platform.OS === 'android' ? Number.MAX_SAFE_INTEGER : undefined // since elevation IS only an android property

or 2)

elevation: Number.MAX_SAFE_INTEGER

or 3)

elevation: 1000 // pick a value, any value

Preferences? Or does someone want to get to the ACTUAL root of the issue?

[reyesr]

I think this issue is also related to #12368 and appears when using Modal on IOS, in a specific context, in debug mode.

I do not use redux, my app actually uses NavigationExperimental (the root component of the display is a NavigationCardStack) and when I display a Modal on IOS in Debug Mode, the render() function freezes and the modal is never displayed. On Android, the very same code works fine in both Normal and Debug Mode.

This freeze happens in 0.42.0-rc3, but NOT in 0.41.2.

I couldn’t create a minimal app that reproduces the bug, as just adding a modal to the default app created after an init’ does not trigger the issue. There is something more, but not sure what makes the issue appear.