[390-48] Install on Debian fails: Unable to load 'nvidia-drm' kernel module

Installing 390-48 AMD64 on GTX970/Sabertooth990 mobo running updated Debian Buster (kernel 4.16.0-1-amd64) fails with the on-screen message

ERROR: Unable to load ‘nvidia-drm’ kernel module.

I’ve then searched the net for obvious answers - no cigar. Chatted with Nvidia Support who instantly sent me here on the first mention of ‘Linux’. Read the pinned info on posting and here goes:

I’ve run the ‘nvidia-bug-report.sh’ script and looked in its output to learn why nvidia-drm won’t load.

It turns out the DKMS buid process chokes on an undefined symbol:
WARNING: “swiotlb_map_sg_attrs” [/var/lib/dkms/nvidia/390.48/build/nvidia.ko] undefined!

However, it seems to finish the build.
Subsequently, the installer tries to load the module, but fails.
Leaving me on th shell with no X.

The forum-sticky instructs me to attach the bug-report tool output. See attached file

Given the above clues, can anyone point me to a sensible Next Step?

The system has been running for a year or so, but upgrading it (simple maintenance) broke the nvidia-driver-install. Again. For the n’th time…

nvidia-bug-report.log.gz (64.6 KB)

For kernel 4.16 you’ll need driver 396.x