What causes "重试 %d 次后失败: %w" in fish2018/pansou?

Inspect the wrapped lastErr with errors.Unwrap/errors.As to see the true root cause (timeout, connection refused, status code).

fish2018/pansou · error

重试次后失败

Error message

重试 %d 次后失败: %w

What it means

alupan's doRequestWithRetry attempts an HTTP request up to maxRetries times with exponential backoff (retryBaseDelay=200ms doubling per attempt). If every attempt fails, it returns the final wrapped error '重试 %d 次后失败: %w' so callers (searchImpl, fetchDetailLinks) know the retries were exhausted, preserving the underlying cause via %w.

Solutions

Inspect the wrapped lastErr with errors.Unwrap/errors.As to see the true root cause (timeout, connection refused, status code).
Verify network connectivity and that the target host is reachable from the environment (curl the endpoint).
Check for rate limiting/IP blocking on the upstream site and raise retryBaseDelay or maxRetries accordingly.
Add a timeout-aware http.Client and, if the site requires it, valid cookies/headers set before the request.

Example fix

// before
results, err := p.searchImpl(keyword)
if err != nil { return nil, err }
// after
results, err := p.searchImpl(keyword)
if err != nil {
    var netErr net.Error
    if errors.As(err, &netErr) && netErr.Timeout() {
        return nil, fmt.Errorf("upstream timed out: %w", err)
    }
    return nil, err // surface wrapped cause for diagnosis
}

Defensive patterns

Strategy: retry

Validate before calling

func isRetryable(err error) bool { var ne net.Error; return errors.As(err, &ne) || errors.Is(err, context.DeadlineExceeded) }

Try / catch

res, err := plugin.Search(keyword)
if err != nil {
    var ne net.Error
    if errors.As(err, &ne) && ne.Timeout() {
        // schedule retry with longer deadline
    } else {
        log.Printf("search failed permanently: %v", err)
    }
}

Prevention

Health-check the upstream host before batch searches
Tune retryBaseDelay/maxRetries to the site's actual latency
Monitor for 429/403 rates and back off proactively
Always inspect the wrapped cause with errors.As/Is

When it happens

Trigger: All maxRetries attempts of the HTTP request inside doRequestWithRetry fail — e.g. the alupan search or detail endpoint is unreachable, times out, or the transport keeps returning non-recoverable errors; called from searchImpl (alupan.go:131) or fetchDetailLinks (alupan.go:261).

Common situations: Target site is down or blocking (403/429), DNS failure, no network access, TLS errors, or a proxy misconfiguration making every retry fail within the backoff window.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

AI-assisted analysis of fish2018/pansou@beaa561337 (2026-09-07). Data as JSON: /api/errors/432cc55eb7d823d0. Report an issue: GitHub.

Appendix: source

Thrown at plugin/alupan/alupan.go:401

func (p *AlupanPlugin) doRequestWithRetry(req *http.Request, client *http.Client, maxRetries int) (*http.Response, error) {
	var lastErr error

	for attempt := 0; attempt < maxRetries; attempt++ {
		resp, err := client.Do(req.Clone(req.Context()))
		if err == nil && resp.StatusCode == http.StatusOK {
			return resp, nil
		}
		if resp != nil {
			resp.Body.Close()
		}
		lastErr = err
		if attempt < maxRetries-1 {
			backoff := retryBaseDelay * time.Duration(1<<attempt)
			time.Sleep(backoff)
		}
	}

	return nil, fmt.Errorf("重试 %d 次后失败: %w", maxRetries, lastErr)
}

func startCacheCleaner() {
	ticker := time.NewTicker(cacheCleanupInterval)
	defer ticker.Stop()

	for range ticker.C {
		now := time.Now()
		detailCache.Range(func(key, value interface{}) bool {
			entry, ok := value.(cacheEntry)
			if !ok || now.After(entry.expiresAt) {
				detailCache.Delete(key)
			}
			return true
		})
	}
}

View on GitHub (pinned to beaa561337)

重试 次后失败