Werner Modenbach <modenbach(at)alc(dot)de> writes:
>> Filedescriptor 0 is STDIN. I would guess pg_dumpall want's to read
>> something from stdin, pherhaps ask you a question?
>>
> But it doesn't ask in interactive (shell) mode.
I was going to suggest that it's trying to read a password. Are you
sure you don't have password authentication enabled?
You might try adding < /dev/null to the cron entry. I would have thought
that would be the default, but perhaps it isn't on your machine.
regards, tom lane