Confidential VM builds - Packer azure plugin crash unexpected EOF

[phochard]

Hi,

We are trying to build an image on Azure using packer.

Our configuration file looks like this :

variable "prefix" {}
variable "client_id" {}
variable "tenant_id" {}
variable "subscription_id" {}
variable "client_secret" {}

locals {
  client_id = "${var.client_id}"
  client_secret = "${var.client_secret}"
  subscription_id = "${var.subscription_id}"
  tenant_id = "${var.tenant_id}"
  ubuntu_managed_image_name = "${var.prefix}-***"
  ubuntu_build_resource_group_name = "***"
  os_type = "***"
  image_publisher = "***"
  image_offer = "***"
  image_sku = "***"
  vm_size = "***"
  vtpm_enabled = true
  secure_boot_enabled = true
  security_type = "***"
}

source "azure-arm" "ubuntu" {
  client_id                 = local.client_id
  tenant_id                 = local.tenant_id
  subscription_id           = local.subscription_id
  client_secret             = local.client_secret
  build_resource_group_name   = local.ubuntu_build_resource_group_name
  os_type                     = local.os_type
  vm_size                     = local.vm_size
  secure_boot_enabled         = local.secure_boot_enabled
  vtpm_enabled                = local.vtpm_enabled
  security_type               = local.security_type
  shared_image_gallery {
    subscription = "***"
    resource_group = "***"
    gallery_name = "***"
    image_name = "***"
    image_version = "***"
  }
  shared_image_gallery_destination {
    resource_group = "***"
    gallery_name = "***"
    image_name = "***"
    image_version = "***"
    storage_account_type = "***"
    target_region {
      name = "***"
    }
  }
}

build {
  sources = ["source.azure-arm.ubuntu"]

}

When running packer build -debug azure-sev-ubuntu.pkr.hcl, Packer crashes even before trying to build the image, it seems like there is an issue with a plugin we are using.
The log file is attached below.

Could someone help us with this error please ?

crash.log

[JenGoldstrich]

Hey @phochard thanks for reporting this and for the crash log and template, this helped me reproduce this issue very quickly, I have a PR open here, I'll work with my team to get this approved and merged, and am planning to release a fix for this shortly after we merge the PR