make check fails: user "postgres" doesn't exist

Hi,

make check fails, and I have absolutely no idea where to look:

running on port 65432 with pid 631
============== creating database "regression"         ==============
createdb: could not connect to database template1: FATAL:  user
"postgres" does not exist
pg_regress: createdb failed
make: *** [check] Ошибка 2

--
Markus Bertheau.
Berlin, Berlin.
Germany.