When I wrote Net::SCP::Expect I added a $SIG{CHLD} handler. I'm sure I had a good reason for doing this...if only I could remember what it was.
Anyhoo, I got my first error report of "No child processes" from someone on a solaris box. Since I don't care about what happens to dead children (we're talking processes here, people) I think this should have just been set to "IGNORE".
We'll see what happens.