Redis::CommandError: ERR Client sent AUTH, but no password is set

This has to be some wrong config

I installed redis on localhost.

When trying to connect to it through Rails console

Redis.new(:host => 'localhost', :port => 6379)

I can't send commands and I get

Redis::CommandError: ERR Client sent AUTH, but no password is set

I don't recall setting a password, nor do I know where to see if a password has been set

if I use a different URL (like rediscloud or redistogo) I can send commands (setting the password accodingly)

From what I understand the error says that I am sending a password, but redis doesn't have a password. But, as you can see, I am not setting any password..

Is there a way to debug this?