FATAL: no PostgreSQL user name specified in startup packet (PGError)

This difficult-to-trace error occurs when you start the app server and you have an error in your database.yml. Instead of

username: user

I had

user: user

Choosing between ruby-postgres and postgres gems

I saw a post saying that postgres and ruby-postgres are the same project (and had the same versions at some point: 0.7.1). This is how I chose to use postgres rather than ruby-postgres. Oh, and that Robby on Rails chooses it in his rails stack for Leopard at Planet Argon.

$ gem search -r postgres

*** REMOTE GEMS ***

postgres (0.7.9.2008.01.28, 0.7.9.2008.01.24, 0.7.9.2008.01.09, 0.7.9.2008.01.03, 0.7.9.2007.12.22, 0.7.9.2007.12.12)
ruby-postgres (0.7.1.2006.04.06, 0.7.1.2006.04.05, 0.7.1.2005.12.21, 0.7.1.2005.12.20, 0.7.1.2005.12.19, 0.7.1.2005.11.27, 0.7.1.2005.11.26, 0.7.1.2005.11.24, 0.7.1.2005.11.23)
$