I just (with the last half hour) grabbed a fresh copy of 7.4 from CVS
and got an error when building contrib/array:
gcc -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -fpic -I. -I../../src/include -c array_iterator.c -o array_iterator.o
array_iterator.c:30: utils/fmgroids.h: No such file or directory
make: *** [array_iterator.o] Error 1
This is on a RH6.2 system.
This is the configure command I used:
./configure --prefix=/usr/local/pgsql --enable-integer-datetimes --with-pgport=5433