handle_error

# File lib/bundler/installer/parallel_installer.rb, line 196
    def handle_error
      errors = @specs.select(&:failed?).map(&:error)
      if exception = errors.find {|e| e.is_a?(Bundler::BundlerError) }
        raise exception
      end
      raise Bundler::InstallError, errors.map(&:to_s).join("\n\n")
    end