The problem was: the Nvidia installer loaded in incompatible version of nvcc (version 11 vs version 12). Now everything is sorted out. Wading into the Nvidia dependencies, the multitude of repositories and libraries, the terrible documentation and support sites, has got to be one of the most awful tasks in computing.
> aptitude search nvidia | wc -l
16684
That’s just for the drivers, not including the userspace modules (cuda, cudnn) 
