class Bundler::GemSource

def download(spec)
  Bundler.logger.info "Downloading #{spec.full_name}.gem"
  destination = repository.path
  unless destination.writable?
    raise RubygemsRetardation, "destination: #{destination} is not writable"
  end
  # Download the gem
  Gem::RemoteFetcher.fetcher.download(spec, uri, destination)
  # Re-read the gemspec from the downloaded gem to correct
  # any errors that were present in the Rubyforge specification.
  new_spec = Gem::Format.from_file_by_path(destination.join('cache', "#{spec.full_name}.gem")).spec
  spec.__swap__(new_spec)
end