test(watchdog): 状态文件先拨回上一轮的时间，Linux 粗粒度 mtime 下备用文件不再和它同刻

	if got := NewestState(path, fallback); got != path {

		t.Fatalf("no fallback yet: NewestState = %q, want the file", got)

	}

	// An earlier run wrote the file, minutes before this one. Linux stamps files

	// from a coarse clock, so two writes a test makes back to back can share an

	// mtime, and a tie reads the file.

	earlier := time.Now().Add(-time.Hour)

	if err := os.Chtimes(path, earlier, earlier); err != nil {

		t.Fatal(err)

	}

	mailed := &State{Recipients: []string{"[email protected]"}}

	run(mailed, Report{Findings: []Finding{finding("memory", Warning, 0)}}, t0)