Why postgresql on mac asks me for password after fresh install?

Question

I just installed postgresql on a Macbook with brew install postgresql. Then I try to psql, but it requires password and then show

Answer 1

So your username probably does not exist, as the default username that ships with the db is postgres.

Further, I was prevented from the submission of an empty password, which is blank by default for the postgres user.

You might try

cd ~/
sudo -u postgres psql -c "ALTER USER postgres PASSWORD 'postgres';"
Password: YOUR_LOGIN_PWD_HERE (required for sudo)

and then to use

psql -U postgres
password: postgres

I'm not 100% sure of which SO answer I got this from, perhaps here. Hope this helps.