https://github.com/rails/rails/issues/11364

active_record_master.rb

require 'bundler'
Bundler.setup(:default)

require 'active_record'
require 'minitest/autorun'
require 'logger'

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'postgresql', database: 'pgintarrtest')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :examples do |t|
    t.integer :int_arr, array: true, default: "{}"
  end
end

Gemfile

source 'https://rubygems.org'
gem 'rails', github: 'rails/rails'
gem 'pg'

Gemfile.lock

GIT
  remote: git://github.com/rails/rails.git
  revision: 4be2003778cdfe06ccaaa2a19040e0cf82dcdde3
  specs:
    actionmailer (4.1.0.beta)
      actionpack (= 4.1.0.beta)
      mail (~> 2.5.4)
    actionpack (4.1.0.beta)
      actionview (= 4.1.0.beta)
      activesupport (= 4.1.0.beta)
      rack (~> 1.5.2)
      rack-test (~> 0.6.2)
    actionview (4.1.0.beta)
      activemodel (= 4.1.0.beta)
      activesupport (= 4.1.0.beta)
      builder (~> 3.1.0)
      erubis (~> 2.7.0)
    activemodel (4.1.0.beta)
      activesupport (= 4.1.0.beta)
      builder (~> 3.1.0)
    activerecord (4.1.0.beta)
      activemodel (= 4.1.0.beta)
      activesupport (= 4.1.0.beta)
      arel (~> 4.0.0)
    activesupport (4.1.0.beta)
      i18n (~> 0.6, >= 0.6.4)
      json (~> 1.7)
      minitest (~> 5.0)
      thread_safe (~> 0.1)
      tzinfo (~> 0.3.37)
    rails (4.1.0.beta)
      actionmailer (= 4.1.0.beta)
      actionpack (= 4.1.0.beta)
      actionview (= 4.1.0.beta)
      activerecord (= 4.1.0.beta)
      activesupport (= 4.1.0.beta)
      bundler (>= 1.3.0, < 2.0)
      railties (= 4.1.0.beta)
      sprockets-rails (~> 2.0.0)
    railties (4.1.0.beta)
      actionpack (= 4.1.0.beta)
      activesupport (= 4.1.0.beta)
      rake (>= 0.8.7)
      thor (>= 0.18.1, < 2.0)

GEM
  remote: https://rubygems.org/
  specs:
    arel (4.0.0)
    atomic (1.1.10)
    builder (3.1.4)
    erubis (2.7.0)
    hike (1.2.3)
    i18n (0.6.4)
    json (1.8.0)
    mail (2.5.4)
      mime-types (~> 1.16)
      treetop (~> 1.4.8)
    mime-types (1.23)
    minitest (5.0.6)
    multi_json (1.7.7)
    pg (0.15.1)
    polyglot (0.3.3)
    rack (1.5.2)
    rack-test (0.6.2)
      rack (>= 1.0)
    rake (10.1.0)
    sprockets (2.10.0)
      hike (~> 1.2)
      multi_json (~> 1.0)
      rack (~> 1.0)
      tilt (~> 1.1, != 1.3.0)
    sprockets-rails (2.0.0)
      actionpack (>= 3.0)
      activesupport (>= 3.0)
      sprockets (~> 2.8)
    thor (0.18.1)
    thread_safe (0.1.0)
      atomic
    tilt (1.4.1)
    treetop (1.4.14)
      polyglot
      polyglot (>= 0.3.1)
    tzinfo (0.3.37)

PLATFORMS
  ruby

DEPENDENCIES
  pg
  rails!