Thread.join exits with SIGUSR1 (SignalException)?

When I start a DRB service like this:


DRb.start_service ‘druby://localhost:9000’, Test.new
DRb.thread.join

It crashes after a while (usually about 2 days) with the following error
message:

/home/erik/test/test:31:in `join’: SIGUSR1 (SignalException)
from /home/erik/test/test:31

I have no idea why it receives that signal, nor what to do about it.

Anybody knows what could be the problem here?

TIA,

Erik.