Sometimes, attempting to run lambdas will return this type of error:
```
{"Type": "Server", "message": "Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists Traceback (most recent call last):\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_api.py\", line 338, in run_lambda\n 
event, context=context, version=version, asynchronous=asynchronous)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 81, in execute\n 
return do_execute()\n File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 70, in do_execute\n self._store_logs(func_details, log_output, invocation_time)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 105, in _store_logs\n logs_client.create_log_group(logGroupName=log_group_name)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 357, in _api_call\n 
return self._make_api_call(operation_name, kwargs)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 661, in _make_api_call\n 
raise error_class(parsed_response, operation_name)\n
botocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists\n", "__type": "InternalFailure"}
```
I am not yet sure if there are any particular settings that cause it, since it does not occur for certain deployments.

Will update if I can figure out the exact configuration.
if ref == 'AWS::Region':
        return aws_stack.get_region()
    resource_status = {}
    if stack_name:
        resource_status = describe_stack_resource(stack_name, ref)
        attr_value = resource_status.get(attribute)
        if attr_value not in [None, '']:
            return attr_value
    elif ref in resources:
        resource_status = resources[ref]['__details__']
    
    resource = resources.get(ref)
    resource_new = retrieve_resource_details(ref, resource_status, resources, stack_name)
    if not resource_new:
        return
    resource_type = get_resource_type(resource)
    result = extract_resource_attribute(resource_type, resource_new, attribute)
    if not result:
        LOG.warning('Unable to extract reference attribute %s from resource: %s' % (attribute, resource_new))
    return result
def resolve_refs_recursively(stack_name, value, resources):