pre := fmt.Sprintf("%s(%q): ", statname, devNullName)
	if fi.Size() != 0 {
		t.Errorf(pre+"wrong file size have %d want 0", fi.Size())
	}
	if fi.Mode()&ModeDevice == 0 {
		t.Errorf(pre+"wrong file mode %q: ModeDevice is not set", fi.Mode())
	}
	if fi.Mode()&ModeCharDevice == 0 {
		t.Errorf(pre+"wrong file mode %q: ModeCharDevice is not set", fi.Mode())
	}
	if fi.Mode().IsRegular() {