class Bundler::Source::Rubygems

def fetch_specs
  index = Index.new
  Bundler.ui.info "Fetching source index from #{uri}"
  old, Gem.sources = Gem.sources, ["#{uri}"]
  fetch_all_specs do |n,v|
    v.each do |name, version, platform|
      next unless Gem::Platform.match(platform)
      spec = RemoteSpecification.new(name, version, platform, @uri)
      spec.source = self
      index << spec
    end
  end
  index.freeze
ensure
  Gem.sources = old
end