remove_source_caches (Gem::Commands::SetupCommand)

    # File lib/rubygems/commands/setup_command.rb, line 334
      def remove_source_caches(install_destdir)
        if install_destdir.empty?
          require 'rubygems/source_info_cache'

          user_cache_file = File.join(install_destdir,
                                      Gem::SourceInfoCache.user_cache_file)
          system_cache_file = File.join(install_destdir,
                                        Gem::SourceInfoCache.system_cache_file)

          say "Removing old source_cache files" if Gem.configuration.really_verbose
          rm_f user_cache_file if File.writable? File.dirname(user_cache_file)
          rm_f system_cache_file if File.writable? File.dirname(system_cache_file)
        end
      end