Interesting:

• bundle install --without test excludes the test group in your Gemfile from the install. It works well for reducing the size of your Heroku slug. However, there’s a glitch with this option on Heroku — when you specify it, Heroku reinstalls every included gem every time you deploy. It does respect your Gemfile.lock, so you’re trading a smaller slug for a longer deploy.

• Pivotal’s open source CIMonitor project now supports OpenID! Thanks Tyler and Josh.

• Arel has a bug that makes it difficult to use in rails console. Every time you add a predicate, the number of internal objects in the Arel result increases exponentially. So, by the time you have 5 or 6 predicates, the console finishes generating the expression more or less instantly, and then spends 15+ minutes calling to_s on the resulting Arel object in order to display it to you. tl;dr: when you’re playing with Arel in rails console, end every line with ; nil to avoid having it print out the result. The exponential object explosion will be fixed in Rails 3.1.