Ruby's pessimistic operator and locking gem versions

Ruby's "twiddle wakka" and why we don't use it

source 'https://rubygems.org' ruby '1.9.3' gem 'bootstrap-sass', '2.1.0.0' gem 'clearance', '1.0.0.rc1' gem 'delayed_job_active_record', '0.3.2' gem 'fog', '1.5.0' gem 'formtastic-bootstrap', '2.0.0' gem 'haml', '3.2.0.beta.3' gem 'high_voltage', '1.2.0' gem 'jquery-rails', '2.1.1' gem 'nested_form', '0.2.2' gem 'newrelic_rpm', '3.4.1' gem 'paperclip', '3.1.4' gem 'pg', '0.14.0' gem 'rails', '3.2.8' gem 'thin', '1.4.1' gem 'will_paginate', '3.0.3' group :test do gem 'bourne', '1.2.0' gem 'database_cleaner', '0.8.0' gem 'capybara-webkit', '0.12.1' gem 'factory_girl_rails', '4.0.0' gem 'launchy', '2.1.2' gem 'shoulda-matchers', '1.2.0' gem 'timecop', '0.4.5' end group :development do gem 'foreman', '0.56.0' gem 'mail_view', '1.0.3' end group :development, :test do gem 'rspec-rails', '2.9.0' end group :assets do gem 'asset_sync', '0.4.2' gem 'coffee-rails', '3.1.1' gem 'sass-...

Full article: http://robots.thoughtbot.com/post/2508037841/rubys-twiddl...