def load_gems_in(*spec_dirs)
    @gems.clear

    spec_dirs.reverse_each do |spec_dir|
      spec_files = Dir[File.join(spec_dir, "*.gemspec")]

      spec_files.each do |spec_file|
        gemspec = Gem::Deprecate.skip_during do
          Gem::Specification.load spec_file
        end
        add_spec gemspec if gemspec
      end
    end

    self
  end
#
Reconstruct the source index from the specifications in +spec_dirs+.