> is displayed again.  This time, entering anything (or just return) always
> gives me the "# " prompt, as if I had launched a shell.
...
> "exit" to the "# " prompt gets me back to the main sysinst screen.

My hypothesis: sysinst called exit() or abort() for some reason, and dropped
you into the single-user mode shell session. When you exit that, it realizes
it can't boot to multi-user, so it restarts single-user mode -- which runs
sysinst like it does when you booted originally. So you get the menu again.

> Any hints on what I'm doing wrong?  (I've installed many NetBSD systems,
> have never seen this happen before.)

I don't think it's your fault. For one thing, this is -current; for another,
I'm not a portmaster (nor do I play one on TV). So I could very well have
missed a step while building these things.

The arm32 snap has also had an installer bug reported against it, but it
shows up as "can't access /etc/disktab" and the root cause was a read-only
root device.

I'll try to take a look at it soon, as it should be straightforward to fix
once we reproduce it. (Anyone else feel free to jump in and report back here,
of course...)

In the meantime, try running "mount -u /kern/rootdev /" (IIRC, you can check
the device name with 'mount' first) and then run sysinst again (do NOT exit
from the shell session, that will make it read-only again). This might get
it working for you.

If so, then most likely there's an extra step involved in building these
install kernels to prevent the memory disk from being read-only by default.

Todd Whitesel
toddpw @ best.com