Error when using .VHD as boot device

[remi-espie]

Overview of the Issue

When using a .vhd as the iso_url (as stated possible in the documentation, VirtualBox returns the error Error attaching ISO: VBoxManage error: VBoxManage.exe: error: The medium '<path/to/vhd>' can't be used as the requested device type (DVD, detected HDD).

Reproduction Steps

Put a .VHD file locaiton as the iso_url and run packer.

Plugin and Packer version

From packer version: Packer v1.10.0

From packer plugins installed:

C:\Users\<Username>\AppData\Roaming\packer.d\plugins\github.com\hashicorp\ansible\packer-plugin-ansible_v1.1.0_x5.0_windows_amd64.exe
C:\Users\<Username>\AppData\Roaming\packer.d\plugins\github.com\hashicorp\hyperv\packer-plugin-hyperv_v1.1.2_x5.0_windows_amd64.exe
C:\Users\<Username>\AppData\Roaming\packer.d\plugins\github.com\hashicorp\vagrant\packer-plugin-vagrant_v1.1.1_x5.0_windows_amd64.exe
C:\Users\<Username>\AppData\Roaming\packer.d\plugins\github.com\hashicorp\virtualbox\packer-plugin-virtualbox_v1.0.5_x5.0_windows_amd64.exe
C:\Users\<Username>\AppData\Roaming\packer.d\plugins\github.com\hashicorp\vmware\packer-plugin-vmware_v1.0.11_x5.0_windows_amd64.exe

Simplified Packer Buildfile

source "virtualbox-iso" "virtualbox" {
  boot_command              = ["a<wait>a<wait>a"]
  boot_wait                 = "-1s"
  cd_files                  = ["./installers"]
  cpus                      = "4"
  disk_size                 = "50000"
  headless                  = "true"
  iso_checksum              = "none"
  iso_url                   = "$<path/to/vhd>"
  memory                    = "4096"
  output_directory          = "./output"
  shutdown_command          = "shutdown /s /t 10 /f /d p:4:1 /c \"Packer Shutdown\""
  guest_os_type             = "Windows10_64"
  vm_name                   = "${var.vm_name}"
}

build {
  sources = ["source.hyperv-iso.hyperv", "source.virtualbox-iso.virtualbox", "source.vmware-iso.vmware"]
  provisioner "breakpoint" {
    name = "debug"
  }
}

Operating system and Environment details

Windows 10 amd64, running from Powershell.

Log Fragments and crash.log files

Link to Packer log gist

Note

When using VirtualBox GUI, I can put the .vhd as a hard drive and run my VM normally, I just don't understand how to do the same with packer.