E3012 "String" recommended for an external template parameter where type is "Number"

cfn-lint version: 0.18.0

I define some of my template with sub-templates and everything is packaged with that kind of command line

aws cloudformation package --template-file ./sources/template-source.yaml --s3-bucket my-bucket-build --output-template-file final-template.yaml 

In template-source I have a resource which type is AWS::CloudFormation::Stack. It’s definition looks like that :

    ManagerService:
        Type: AWS::CloudFormation::Stack
        Properties:
            TemplateURL: ../../../common/service.yaml
            Parameters:
                Cluster: !Ref Cluster
                DesiredCount: 1

Here is the definition of the parameter in my service template :

Parameters: 

    Cluster:
        Description: Please provide the ECS Cluster ID that this service should run on
        Type: String
        
    DesiredCount: 
        Description: How many instances of this task should we run across our cluster?
        Type: Number
        Default: 1

And cfn-lint return the following error :

cfn-lint source-template.yaml
E3012 Property Resources/ManagerService/Properties/Parameters/DesiredCount should be of type String

It says that type should be a String, but the type in the template is define as Number. Am I missing something ?

Thanks for your help

[BatmanTheBlind]

For the moment, I’ve disabled the check with the follwing .cfnlintrc file :

include_checks:
- I
configure_rules:
  E3012:
    strict: False

[phene]

@kddejong List parameters do not pass through to sub stacks successfully. If you have a CommaDelimitedList type in your main stack and you attempt pass it through to a CommaDelimitedList in the sub stack, you will get a failure. Only types that can be coerced to strings can be passed through to a substack, like numbers and booleans.

The only way to pass a list through is to !Join [',', !Ref MyList] as you pass it through to the sub stack.

I think configuring E3012 with strict: False would do the trick here.