Unexpected response from resource of type compute.v1.autoscaler: 400
{
    "code": 400,
    "errors": [
        {
            "domain": "global",
            "message": "Invalid value for field 'resource.target': 'https://www.googleapis.com/compute/v1/projects/XXX/zones/ZZZ/instanceGroupManagers/instance-group-manager'. Target already referenced by Autoscaler.",
            "reason": "invalid"
        }
    ],
    "message": "Invalid value for field 'resource.target': 'https://www.googleapis.com/compute/v1/projects/XXX/zones/ZZZ/instanceGroupManagers/instance-group-manager'. Target already referenced by Autoscaler.",
    "requestPath": "https://www.googleapis.com/compute/v1/projects/XXX/zones/ZZZ/autoscalers",
    "statusMessage": "Bad Request"
}

resources:
  - name: backend-igm
    type: compute.v1.instanceGroupManager
    properties:
      zone: ZZZ
      targetSize: 1
      baseInstanceName: backend-instance
      instanceTemplate: https://www.googleapis.com/compute/v1/projects/XXX/global/instanceTemplates/my-template

  - name: backend-as
    type: compute.v1.autoscaler
    properties:
      zone: ZZZ
      target: $(ref.backend-igm.selfLink)
      autoscalingPolicy:
        minNumReplicas: 1
        maxNumReplicas: 2