Cross-stack dependencies?

[thelpbogeyman]

I am having trouble resolving a dependency during a serverless deploy that has nested stacks.
The issue is with a subscription filter:

MyAPIGatewaySubscriptionFilter:  
 Type: "AWS::Logs::SubscriptionFilter"  
 DependsOn:  
   - ApiGatewayLogGroup  
 Properties:  
 DestinationArn: ${self:custom.lambda-arn}  
 LogGroupName: !Ref 'ApiGatewayLogGroup' # "/aws/api-gateway/${self:service}-${self:provider.stage}"  
 FilterPattern: ""  

MyAPIGatewayExecutionLogSubscriptionFilter:
  Type: "AWS::Logs::SubscriptionFilter"
  DependsOn:
    - ApiGatewayLogGroup
  Properties:
    DestinationArn: ${self:custom.lambda-arn}
    LogGroupName:  # https://docs.aws.amazon.com/apigateway/latest/developerguide/view-cloudwatch-log-events-in-cloudwatch-console.html
      Fn::Join:
        - ""
        - - API-Gateway-Execution-Logs_
          - !Ref 'ApiGatewayRestApi'
          - "/${self:provider.stage}"
    FilterPattern: ""

The fist subscription (MyAPIGatewaySubscriptionFilter is created successfully).

For the second one, on the execution log (MyAPIGatewayExecutionLogSubscriptionFilter), the error I am getting is this: Embedded stack arn:aws:cloudformation:us-west-2:123456789012:stack/mystackname-mystagename-LogGroupNestedStack-RFNWRESNSMPO/87d10e90-01eb-11ec-9666-0a842ba78b03 was not successfully created: The following resource(s) failed to create: [MyAPIGatewayExecutionLogSubscriptionFilter].

I am trying to figure out how to set a dependency upon the creation of the execution log.

If I remove the MyAPIGatewayExecutionLogSubscriptionFilter resource from the YAML, the execution log is successfully created. - but the subscription is obviously not created.

I'm using "serverless-plugin-split-stacks": "1.9.3", in package.json and have it specified in the plugins: section in serverless.yml.

Firstly, in serverless.yml, my setting are set as follows:

  splitStacks: # explicitly disable perXXX features. use stacks-map.js for custom.
    perFunction: false
    perType: false
    perGroupFunction: false

In the stacks configuration (stacks-map.js), I've tried this:

module.exports = (resource, logicalId) => {
  if (
    logicalId.startsWith('ServerlessDeploymentBucket') ||
    logicalId.startsWith('ApiGatewayResource') ||
    logicalId.startsWith('ApiGatewayRestApi') ||
    logicalId.endsWith('LambdaExecution' ||
    logicalId === 'HandleEventsLambdaFunction'
    )
  ) return false

  if (resource.Type === 'AWS::Lambda::Function' || resource.Type === 'AWS::ApiGateway::Method') return { destination: 'Lambda' }
  if (resource.Type === 'AWS::Lambda::EventSourceMapping') return { destination: 'EventSourceMapping' }
  if (resource.Type === 'AWS::CloudWatch::Alarm') return { destination: 'Alarm' }
  if (resource.Type === 'AWS::Events::Rule') return { destination: 'Rule' }
  if (resource.Type === 'AWS::Kinesis::Stream') return { destination: 'Stream' }
  if (resource.Type === 'AWS::Logs::LogGroup' || resource.Type === 'AWS::Logs::SubscriptionFilter') return { destination: 'LogGroup' }
  if (resource.Type === 'AWS::DynamoDB::Table') return { destination: 'Table' }
}