Cannot define a default route table route with an IPv6 CIDR.

[richardgavel-ordinaryexperts]

Description

Can not add IPv6 routes to default route table.

Versions

• Module version [Required]: 5.8.1

• Terraform version:
  1.7.x

• Provider version(s):
  5.30.x

Reproduction Code [Required]

module "vpc" {
  default_route_table_routes = [
    {
      gateway_id                 = "igw-026553dd16e3604fe"
      ipv6_cidr_block            = "::/0"
    }
  ]
}

Expected behavior

Route added to default route table

Actual behavior

Error

│ Error: Missing map element
│ 
│   on .terraform/modules/vpc/main.tf line 1353, in resource "aws_default_route_table" "default":
│ 1353:       cidr_block      = route.value.cidr_block
│     ├────────────────
│     │ route.value is map of string with 2 elements
│ 
│ This map does not have an element with the key "cidr_block".

Additional context

Issue is that the cidr_block is a required field, even though in the comment above it says "one of the following must be required".

https://github.com/terraform-aws-modules/terraform-aws-vpc/blob/master/main.tf#L1340