[huge build]
> The current tradeoff is to make that diagnostic based on the running
> kernel, even if it’s an approximation.

Ah, good point.

> If that’s fine with you I’d like to fix this bug with the conservative
> patch below.

Sure, looks good.

While we are approximating we could also in a later version fall back to
(the host system's) "`cat /proc/sys/kernel/modprobe` --showconfig" - it
could be used to find aliases.

But maybe that would make it brittle.  Hmm...