The problem with the different definitions of psignal etc. in unistd.h
vs signal.h and stdlib.h is solved. It was a #define const /* nothing */
in another header file of the application :-| (not my own one, but I
won't betray the rogue :-). Thanks to jtc for the hint. NetBSD is the best
unix I know - but I don't like unix very much... :->

Henry