# File activesupport/lib/active_support/testing/isolation.rb, line 36
def run_in_isolation(&blk)
  IO.pipe do |read, write|
    read.binmode
    write.binmode

    pid = fork do
      read.close
      yield
      begin
        if error?
          failures.map! { |e|
            begin
              Marshal.dump e
              e
            rescue TypeError
              ex = Exception.new e.message
              ex.set_backtrace e.backtrace
              Minitest::UnexpectedError.new ex
            end
          }
        end
        test_result = defined?(Minitest::Result) ? Minitest::Result.from(self) : dup
        result = Marshal.dump(test_result)
      end

      write.puts [result].pack("m")
      exit!(0)
    end

    write.close
    result = read.read
    _, status = Process.wait2(pid)
    return status, result.unpack1("m")
  end
end