Looks to me like a pthread error?
The annoying this is I had this installed fine from pkgsrc-wip,
I just thought I'd rebuild it again from it's new home to shut
up pkg_chk and here I am , screwed.
The kernel is a bit manky (1.6X) but it was ok from wip, like
I say - it's the same compiler I used (about a fortnight ago) too....

gmake[2]: Leaving directory `/usr/work/databases/postgresql74-client/work/postgresql-7.4.2/src/backend/parser'
gcc -O2 -pipe -I/usr/pkg/include/postgresql -I/usr/include -fno-strict-aliasing -Wall -Wmissing-prototypes -Wmissing-declarations pg_dump.o common.o pg_backup_archiver.o pg_backup_db.o pg_backup_custom.o pg_backup_files.o pg_backup_null.o pg_backup_tar.o dumputils.o ../../../src/backend/parser/keywords.o -lpq -L../../../src/port -L/usr/pkg/lib -Wl,-R/usr/pkg/lib -L/usr/lib -Wl,-R/usr/lib  -L/usr/lib -Wl,-R/usr/pkg/lib -lssl -lcrypto -lz -lreadline -lcurses -lcrypt -lresolv -lcompat -lm -lutil -lintl -lpgport -o pg_dump
/usr/work/databases/postgresql74-client/work/.buildlink/lib/libpq.so: undefined reference to `pthread_mutex_unlock'
/usr/work/databases/postgresql74-client/work/.buildlink/lib/libpq.so: undefined reference to `pthread_mutex_lock'
gmake[1]: *** [pg_dump] Error 1
gmake[1]: Leaving directory `/usr/work/databases/postgresql74-client/work/postgresql-7.4.2/src/bin/pg_dump'
gmake: *** [all] Error 2
*** Error code 2

Stop.
make: stopped in /usr/pkgsrc/databases/postgresql74-client
*** Error code 1


-- 
DeVries's Dilemma:
	If you hit two keys on the typewriter, the one you don't want
hits the paper.
Rasputin :: Jack of All Trades - Master of Nuns