I found this by googling the error message: http://archives.postgresql.org/pgsql-ports/1998-06/msg00005.php.

Basically, the author's install works differently. The fix in the above case was to change Makefile definitions which look like:

INSTLOPTS= -c -m 444 
INSTL_EXE_OPTS= -c  -m 555 
INSTL_LIB_OPTS= -c -m 644
[download]

to:

INSTLOPTS=   -m 444 -c
INSTL_EXE_OPTS=  -m 555 -c
INSTL_LIB_OPTS=  -m 644 -c
[download]