// We expect an error here.
	if err == nil {
		t.Logf("%s", output)
		t.Fatalf("running 'harness -tp %s': did not get expected error", tp)
	}

	got := strings.TrimSpace(string(output))
	want := "WriteCounters invoked for program built"
	if !strings.Contains(got, want) {
		t.Errorf("running 'harness -tp %s': got:\n%s\nwant: %s",
			tp, got, want)
	}

	upmergeCoverData(t, edir, naMode)