### Terraform Version ```shell Terraform v1.9.2 on darwin_arm64 + provider registry.terraform.io/hashicorp/aws v5.93.0 ``` ### Terraform Configuration Files ```terraform import { to = aws_network_acl.acl_0128427005ff54a53 id = "acl-0128427005ff54a21" } ``` ### Debug Output ``` Error: "" is not a valid CIDR block: invalid CIDR address:. ``` ### Expected Behavior Terraform should generate empty cidr blocks as null, or omit them. ```hcl resource "aws_network_acl" "acl_0adfdfbf60d3f9a21" { egress = [{ action = "allow" cidr_block = "0.0.0.0/0" from_port = 0 icmp_code = 0 icmp_type = 0 ipv6_cidr_block = null # or emitted protocol = "-1" rule_no = 50 to_port = 0 }, ... ``` ### Actual Behavior Terraform generate cidr_blocks as "" if unused causing validation to fail on plan as "" is not a valid format for ipv6_cidr_blocks ```hcl resource "aws_network_acl" "acl_0adfdfbf60d3f9a21" { egress = [{ action = "allow" cidr_block = "0.0.0.0/0" from_port = 0 icmp_code = 0 icmp_type = 0 ipv6_cidr_block = "" protocol = "-1" rule_no = 50 to_port = 0 }, ... ``` ### Steps to Reproduce ```hcl import { to = aws_network_acl.acl_0128427005ff54a53 id = "acl-0128427005ff54a21" } ``` ```bash terraform plan -generate-config-out=generated.tf ``` ### Additional Context `Optional: true` should represent `Null`, instead of `Default Zero Type` of `""` ### References - https://github.com/hashicorp/terraform-provider-aws/issues/42087 ### Generative AI / LLM assisted development? N/A