I have seen a deadlock of the YaST2 installation screen during download of some
packages caused by a temporary network hickup ... I had run strace -f -p <pid
of y2base> on virtual console 2 to see that the process does not return from
polling.  Further invertigation had shown that a pipe had been stuck but the
pipe from fd 19 to fd 20 was still there.

As this was in the ram installation disk I've no log about that.  After
terminationg and redoing upgrade from within linuxrc I had h'finished the
installation.

IMHO there a timeout handler for such pollings is missed here!