This morning I had installed Oracle VBox in a KVM virt nested Ubuntu 22.04 VM...

Because the current kernel is 6.5 in the 22.04 HWE stack, the VBox kernel modules will fail to build unless you install gcc-12 & g++-12. Then the modules will build fine.

To build the vbox drivers, the version of the gcc compiler needs to be the same version as what the Kernel was compiled with, just liek nVidia drivers.