On 8/2/06, Darrin Chandler <dwchandler@stilyagin.com> wrote:
> On Wed, Aug 02, 2006 at 02:18:30PM +0100, Gavan Fantom wrote:
> >
> > It does rather look like a break was received on the console. "comintr"
> > in the backtrace is telling here.
>
> This hasn't happened to me, but it has come up a few different times on
> another list. Apparently it's common enough for some machines to send a
> break on shutdown, startup or both. One person was having a hard time
> figuring out what was wrong with their headless box. As long as they
> were watching via serial everything was ok, so they'd leave the cable on
> and shut down the serial "head" machine, and the headless box wouldn't
> work. Start up the "head" machine again and see ddb>! Took them a while
> before they realized the correlation.
>
> It's easiest to get into the habit of only connecting serial when you're
> using it, or plug it into something that stays up.
>

This was common-enough on sun to allow for an alternate break sequence
to be configured.
Also, hyperterm for windows has a bad habit of sending breaks when it
exits.  (unplug and then quit the program)