postgresql: CREATE ROLE does not work

I get the error FATAL role does not exist when doing a rake db:create:all.

The post here asks the same question, except that the answer doesn't work.

Travis CI: FATAL: role does not exist

I get to the postgresql console this way: 'sudo -u postgres psql'

Typing

CREATE ROLE X SUPERUSER 
CREATE ROLE X CREATEDB LOGIN 

or anything for that matter, at the postgres=# prompt does nothing. Absolutely nothing. It doesn't give me a success or fail message or any acknowledgement message whatsoever.

When I type \du to list roles, only the postgres role is there.