Still happens with next-20080901, also upon closer look it is not
just an innocent trace dump as /proc/sys/kernel/pty/ dir and its
content are gone.

That would not surprise me. The 0901 tree would have been built at the end of the weekend. I don't actually work 7 days a week, but 5.

I've pushed that (including a new implementation of the needed field) tonight.

Alan