Cannot run the root-example

[maxsxu]

Environment

• Terraform v1.1.7 on darwin_amd64

Reproduce

Execute terraform apply under the examples/root-example directory will got below errors:

╷
│ Error: Reference to undeclared input variable
│ 
│   on main.tf line 32, in provider "aws":
│   32:   region = var.region
│ 
│ An input variable with the name "region" has not been declared. This variable can be declared with a variable "region" {} block.
╵
╷
│ Error: Reference to undeclared local value
│ 
│   on main.tf line 57, in module "sn_cluster":
│   57:   cluster_name             = local.cluster_name
│ 
│ A local value with the name "cluster_name" has not been declared.
╵
╷
│ Error: Reference to undeclared input variable
│ 
│   on main.tf line 75, in module "sn_cluster":
│   75:   region             = var.region
│ 
│ An input variable with the name "region" has not been declared. This variable can be declared with a variable "region" {} block.