OK, this is sort of the answer.
Previously a start of any Virtual Machine under my Ubuntu 21.10 failed. The problem from VMWare's perspective was
Could not open /dev/vmmon: No such file or directory.
Please make sure that the kernel module `vmmon' is loaded.
(and vmnet also)
This command: sudo vmware-modconfig --console --install-all gave this error (and still does!)
Skipping BTF generation for /tmp/modconfig-9O1P2c/vmmon-only/vmmon.ko due to unavailability of vmlinux
SOLUTION
In my situation I was making a move of a Virtual machine from a Windows platform to a Ubuntu laptop installed with secure boot
Although the above compilation was not perfect it WAS CREATING the necessary binaries, but because they are not signed they cannot be loaded at Ubuntu boot time
So I got the BTF error messages that I thought was preventing VMNware to start but I was wrong.
This link https://github.com/mkubecek/vmware-host-modules/issues/87#issuecomment-800051833 explains the torture necessary to sign the binaries
generate a key
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=VMware/"
import to UEFI database
sudo mokutil --import MOK.der (generate a password need next step)
reboot system and import in UEFI BIOS
(use same password)
sudo shutdown -r now
once rebooted need to sign the binaries
sudo kmodsign sha256 ./MOK.priv ./MOK.der $(modinfo -n vmmon)
sudo kmodsign sha256 ./MOK.priv ./MOK.der $(modinfo -n vmnet)
on reboot new signed binaries used
sudo shutdown -r now
now good to start VMware and use any VM
Once the UEFI BIOS is informed and the driver binaries signed then VMware can operate fine and the world is saved again
So I did not totally fix the compilation issue, but it seems I was conflating this error message with the inability of VMware to run, which was wrong.
