class Bundler::SpecSet

def lookup
  @lookup ||= begin
    lookup = Hash.new { |h,k| h[k] = [] }
    specs = @specs.sort_by do |s|
      s.platform.to_s == 'ruby' ? "\0" : s.platform.to_s
    end
    specs.reverse_each do |s|
      lookup[s.name] << s
    end
    lookup
  end
end