class Bundler::RubygemsIntegration

def spec_cache_dirs
  @spec_cache_dirs ||= begin
    dirs = gem_path.map {|dir| File.join(dir, 'specifications')}
    dirs << Gem.spec_cache_dir if Gem.respond_to?(:spec_cache_dir) # Not in Rubygems 2.0.3 or earlier
    dirs.uniq.select {|dir| File.directory? dir}
  end
end