Ubuntu 22.04 Server unattended install fails with error isolinux.cfg not found

[stcp]

Trying to perform an unattended install of Ubuntu 22.04 Server AMD64 on an Intel CPU MacBook Pro 2011 and I am getting the error message below.

Setup:

• macOS 12.3.1 on MacBook Pro 2018 (with Intel CPU)
• VirtualBox 6.1.34
• Ubuntu Live Server 20.04 AMD64: ubuntu-22.04-live-server-amd64.iso

Serving up user-data and meta-data with a python server on port 3003, based on a Ubuntu Server doc called autoinstall-quickstart.

Getting the following error message:

VBoxManage: info: Preparing unattended installation of Ubuntu_64 in machine 'axxxxx' (b7e7ff1a-1f41-4320-8e9f-c84a2cxxxxxx).
VBoxManage: error: Failed to open '/isolinux/isolinux.cfg' on the ISO '/Users/sxxxxx/dev/vm/iso/ubuntu-22.04-live-server-amd64.iso' (VERR_PATH_NOT_FOUND)
VBoxManage: error: Details: code VBOX_E_FILE_ERROR (0x80bb0004), component UnattendedWrap, interface IUnattended, callee nsISupports
VBoxManage: error: Context: "ConstructMedia()" at line 1859 of file VBoxManageMisc.cpp

The files in the isolinux folder are no longer needed, because the server autoinstall is no longer based on the debian-installer (aka d-i), but rather it is based on Subiquity. Therefore, the VBoxManage unattended installer should not be looking for these. I'm afraid that this might require a VBoxManage upgrade or patch to support the new 'cloud-init' and 'curtin' with 'subiquity' based installer, unless someone can come up with a neat workaround or maybe a new unattended install template.

From browsing the source code under UnattendedTemplates/ubuntu_preseed.cfg that the template is entirely based on the debian-installer (ubiquity) and seems to have no knowledge of the new installer (subiquity).

See the source code under: /browser/vbox/trunk/src/VBox/Main/UnattendedTemplates/ubuntu_preseed.cfg on VirtualBox dot org.

Thanks in advance!