Inaccurate diagnostics context for nested fields

[radeksimko]

Terraform Version

369d512e22bf18fd810b8583e6914458abc569aa

Terraform Configuration Files

resource "azurerm_kubernetes_cluster" "aks_with_rbac" {
  name                = "something"
  location            = "test"
  resource_group_name = "tada"
  dns_prefix          = "radek"
  kubernetes_version  = "1.11"

  role_based_access_control {
    enabled = true
  }

  agent_pool_profile {}
  service_principal {
    client_id     = "00000000-0000-0000-0000-000000000000"
    client_secret = "00000000000000000000000000000000"
  }
}

Expected Behavior

Snippet of code pointing to the right LOC - i.e. to the definition of parent block which is missing arguments.

Actual Behavior

$ terraform plan

Error: Missing required argument

  on main.tf line 1, in resource "azurerm_kubernetes_cluster" "aks_with_rbac":
   1: resource "azurerm_kubernetes_cluster" "aks_with_rbac" {

The argument "name" is required, but no definition was found.

Error: Missing required argument

  on main.tf line 1, in resource "azurerm_kubernetes_cluster" "aks_with_rbac":
   1: resource "azurerm_kubernetes_cluster" "aks_with_rbac" {

The argument "vm_size" is required, but no definition was found.

Steps to Reproduce

$ terraform plan

Additional Context

As documented the arguments reported as missing are arguments nested under agent_pool_profile block, which is not obvious from the error output.

[apparentlymart]

The language used in these errors looks like the language produced by HCL itself when asked to decode a block with a missing required argument, so I'm not sure if this is actually an SDK bug or an HCL bug. Will need to dig in some more to see what's missing here.

[apparentlymart]

I've now seen this same behavior in a different program, so this seems to be a bug either in hcldec or in the lower-level body.Content method it is built on.