OSX Lion: Postgres could not connect to database postgres (after homebrew installation)

Problem:

createuser: could not connect to database postgres: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket “/var/pgsql_socket/.s.PGSQL.5432″?

Solution:

I tried many solutions found across the interwebs to no avail. The problem seems quite common, for me the fix was:

Make sure the daemon is indeed running:

ps aux | grep postgres

Find this .s.PGSQL.5432 file:

sudo find / -name .s.PGSQL.5432

Create a Symbolic Link to the destination it’s “supposed to be located at”:

ln -s /private/tmp/.s.PGSQL.5432 /var/pgsql_socket/

Other Possible Solutions

• Try uninstalling postgresql (brew uninstall postgresql), uninstalling the pg gem (gem uninstall pg), move /usr/local/bin to the first line of /etc/path, reboot, install postgresql, install pg gem, more details instructions here: http://russbrooks.com/2010/11/25/install-postgresql-9-on-os-x
• See Comments here: http://ntcncp.net/2011/09/05/step-by-step-from-setting-up-rails-3-1-development-environment-to-deploying-to-heroku/
• http://www.postgresql.org/docs/8.3/static/server-start.html
• http://stackoverflow.com/questions/6770649/repairing-postgresql-after-upgrading-to-osx-10-7-lion