module Bundler::SharedHelpers

def find_gemfile
  return ENV['BUNDLE_GEMFILE'] if ENV['BUNDLE_GEMFILE']
  previous = nil
  current  = File.expand_path(Dir.pwd)
  until !File.directory?(current) || current == previous
    filename = File.join(current, 'Gemfile')
    return filename if File.file?(filename)
    current, previous = File.expand_path("..", current), current
  end
end