Recursive !Sub is not resolved correctly

[pkit]

I.e:

provider:
  environment:
    DATA_API_RESOURCE_ARN: !Sub arn:aws:rds:${AWS::Region}:${AWS::AccountId}:cluster:${DBCluster}

will be resolved to (in the .env file):

DATA_API_RESOURCE_ARN=arn:aws:rds:${AWS::Region}:${AWS::AccountId}:cluster:${DBCluster}

expected to resolve to:

DATA_API_RESOURCE_ARN=arn:aws:rds:us-east-1:123456789011:cluster:stack-name-stage-dbcluster-SG455Y33

[orr-levinger]

same for me