# File lib/bundler/rubygems_integration.rb, line 96
    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