This weekend, we have an unique opportunity to get involved (or attempt to) in the Rails core development: the Rails Bugmash, organized by RailsBridge. The idea is to resolve as many bugs as possible on the stable version of Rails (2.3.x) - with some assistance of established Rails core members (through IRC on Freenode #railsbridge). A level of playfulness, or competition, is added by the fact that you get awarded points for bug reduction, and there's a few small prizes. The main prize, in my opinion, is the opportunity to participate to a well-managed open source project like Rails.

You'll find relevant information here. And what to do to have your environment ready: here. The railscast is also a good intro.

A few notes that might be useful:

• Update: Install rvm of course !! I installed a variant of Relevance's ruby switcher. I'm using zsh myself, not bash: if this is your case, you'll find the relevant dotfiles in the spicy-code's repository. Good source of inspiration, but since I'm fairly happy with my configs, I just took over ruby_switcher.rb and ruby_installer.rb. Since I didn't want to reinstall versions i already had on my machine, I changed ruby_switcher.rb to use the paths of existing installations (look at the update_path function to see what to use) and then i added the following line to my .zshrc . source /.zsh/ruby_switcher.zsh

• To run the activerecord test set, you need a few databases, and a user 'rails'.

    create user rails;
    create database activerecord_unittest;
    create database activerecord_unittest2;
    grant all on activerecord_unittest.* to rails@localhost;
    grant all on activerecord_unittest2.* to rails@localhost;
    

on postgres the grants of course are

    create user rails password 'password';
    grant all on database activerecord_unittest to rails;
    grant all on database activerecord_unittest2 to rails;
    

Strictly speaking, you need to test on as many dbs at possible - i've got mysql, posgres and (duh) sqlite3 - might add the jdbc's to that list.
You can change configs in activerecord/test/connections/native_/connection.rb . For mysql, I had to add my :socket in there, which defaulted to something strange. For postgres, i had to add user and password (though i suppose you could grant to PUBLIC). If you want to just test activerecord for one type of database, you go into the activerecord directory, and do

    rake test_mysql
    rake test_postgresql
    

and similar. In fact, it's adviseable to run ONLY the tests you need at first, because the test set is obviously sizeable, and takes a wee while to run (using env variable TEST=). Note: I must be missing a grant for postgresql, because i get a load of errors - I'll update if i fix this Update: i ended up using the superuser.

• You also need to start memcached. 11211 is the default port.

    memcached -p 11211 -d
    

• especially this week-end, i'd do git pull regularly, to avoid surprises.

Interesting, anyway.