Recent MapView issue in Expo standalone Android - expo

Question

This is a new issue, seemingly something to do with google maps API - came out of nowhere for us. It seems impossible but our production app suddenly started throwing an occasional error on our startup screen. Our startup screen is mostly a google Map, which is MapView for expo.
Uncaught Error: Error using newLatLngBounds(LatLngBounds, int): Map size can't be 0. Most likely, layout has not yet occured for the map view. Either wait until layout has occurre or use newLatLngBounds(LatLngBounds, int, int, int) which allows you to specify the map's dimensions.
This only happens on our Android standalone app, through Expo it works fine.
We followed the docs for Android: https://docs.expo.io/versions/v34.0.0/workflow/configuration/#android - we’ve went through these steps. To the best of our knowledge we’ve done the process twice with different API keys, and we get the same result.
We’ve tried fixes suggested here, namely setting height and width based on dimensions, setting flex:1, and setting initialLocation. We use onReady to call the initial start method. Nothing seems to work.
The github link above does have someone running into this as of today. Any ideas how to even debug this?

Answer 1

We just removed everything except the map, including removing markers - and it works. We found the issue only happens when we add a marker with a coordinate, we reproduced this on a new brand new expo app by passing in coordinates to the map, and that caused it to crash on Android (most of the time, but not all) when we build and loaded the APK.
Adding markers through the onReady attribute of a map also didn't stop the crashes.
Turns out it's a non-documented method called onLayout, which is only referenced in the doc for fitToCoordinates. It mentions if this function is called to early then it causes a crash, and you may need to use onLayout. We never called fitToCoordinates but apparently something else inside the MapView does.
Someone put the issue here.
We moved our marker creation logic from onReady to onLayout and it worked.
<MapView
testID="map"
style={{flex: 1}}
onMapReady={this.onMapReady}>
{this.mapIsReady && <Marker
key={id}
coordinate={coordinate}/> }
</MapView>
To:
<MapView
...
onLayout={this.onMapReady}
No more crashes...