[IOS] snapshotManager.takeSnap() doesn't work

[damacchi]

Describe the bug
When i use MapboxGL.snapshotManager.takeSnap(options) i get this error:
Error: Could not create snapshot

The error comes from this function in MGLSnapshotModule.m
and there is no script for MGLMapSnapshotter in the repo.

RCT_EXPORT_METHOD(takeSnap:(NSDictionary *)jsOptions
                  resolver:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject)
{
    dispatch_async(dispatch_get_main_queue(), ^{
        MGLMapSnapshotOptions *options = [self _getOptions:jsOptions];
        MGLMapSnapshotter *snapshotter = [[MGLMapSnapshotter alloc] initWithOptions:options];
        
        [snapshotter startWithCompletionHandler:^(MGLMapSnapshot *snapshot, NSError *err) {
            if (err != nil) {
                reject(@"takeSnap", @"Could not create snapshot", err);
                return;
            }
            
            NSString *result = nil;
            if ([jsOptions[@"writeToDisk"] boolValue]) {
                result = [RNMBImageUtils createTempFile:snapshot.image];
            } else {
                result = [RNMBImageUtils createBase64:snapshot.image];
            }
            
            resolve(result);
        }];
    });
}

To Reproduce
Just try to take a snapshot with snapshot manager.

Expected behavior
It should return an uri or a base64 file

Versions (please complete the following information):

• Platfrom: iOS
• React Native Version 0.59
• SDK: 7.0.0-rc3

[mutablestudio]

also getting this error on same versions as above w iOS 12.4 - btw works fine on Android API 28 / Pixel 3

[Unhandled promise rejection: Error: Could not create snapshot]
- node_modules/react-native/Libraries/BatchedBridge/NativeModules.js:155:41 in createErrorFromErrorData
- node_modules/react-native/Libraries/BatchedBridge/NativeModules.js:104:55 in <unknown>

[doomsower]

The native error is MGLMapSnapshotter deallocated prior to snapshot completion