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I'm trying to use ActiveRecord on the latest MacOS X Tiger, but it gives me this error when I try to use my subclass of ActiveRecord::Base (after calling establish_connection)

LoadError: no such file to load — dbi

method require
in ar.rb at line 1
at top level
in ar.rb at line 1

I installed DBI several times and it is there, but can't find it. Here's the source (ar.rb)

require 'dbi'
require 'pp'
require 'rubygems'
require_gem 'activesupport'
require_gem 'activerecord'
#require 'active_record'

:adapter => 'sqlserver',
:database => 'ETT',
:mode => 'ODBC',
:dsn => 'Dev',
:username => 'ETT_sa',
:password => 'MR#Fko[!Iu',
:host => ''

class Order < ActiveRecord::Base

pp { |col| }
pp Order.columns_hash['shipped_at']