Loading shared object files into Postgres

Hello,
I have issued the "make" command for the $PGROOT/src/tutorial/Makefile
file and then issued

load '/home/postgres/linux/src/tutorial/complex.so'

from interactive psql to load the object file into the address space and
received the following:

"PQexec() -- Request was sent to backend, but backend closed the channel
before responding.
This probably means the backend terminated abnormally before or
while processing the request."

What does that mean? What is wrong?

Kostas Vassiliadis