Rails not using Postgres user account -

i'm using rails 3.0 , postgresql 8.4 on ubuntu 10.10 , ruby 1.9.2p136 pg gem. when run rake db:migrate, error fatal: password authentication failed user "my_os_user_account", when expected log in database my_db_username specified in database.yml.

i have md5 authentication configured in pg_hba.conf both unix socket , ip connections , can log in using psql on command line. have tried setting authentication trust. psql allows me log in without entering password, rails gives fatal: role "my_os_user_account" not exist.

here's database.yml:

development:   adapter: postgresql   database: my_project_dev   user: my_db_username   password: my_password   pool: 5   timeout: 5000 

with additional near-identical entries test , production.

the correct key username is, in fact, username , not user. easy mistake, easy fix.