What causes "读取响应失败: %w" in fish2018/pansou?

Retry — this class of error is usually transient

fish2018/pansou · error

读取响应失败

Error message

读取响应失败: %w

What it means

pan666's fetchPage returns this when io.ReadAll(resp.Body) fails on the last retry. A response was received but the body stream broke mid-read — connection reset, premature close, or transfer interrupted. Earlier attempts retry after 500ms; the final one surfaces the io error wrapped.

Solutions

Retry — this class of error is usually transient
Check network path stability (proxy, VPN, firewall) between client and pan666 API
Confirm the server isn't closing connections early (curl -v, check Content-Length vs received bytes)
Disable aggressive connection reuse/keep-alive tuning if stale sockets cause resets

Example fix

// before
responseBody, err = io.ReadAll(resp.Body)
if err != nil {
    if i == p.retries { return nil, false, fmt.Errorf("读取响应失败: %w", err) }
// after
responseBody, err = io.ReadAll(io.LimitReader(resp.Body, 10<<20))
if err != nil {
    if errors.Is(err, io.ErrUnexpectedEOF) && i < p.retries { time.Sleep(500 * time.Millisecond); continue }

Defensive patterns

Strategy: retry

Try / catch

if err != nil {
    if errors.Is(err, io.ErrUnexpectedEOF) {
        time.Sleep(1 * time.Second)
        return fetchPageRetry(offset) // full re-fetch; partial body is unusable
    }
    return err
}

Prevention

Never parse partial bodies — always refetch on read error
Use io.LimitReader to cap body size
Prefer fresh connections over reused keep-alive sockets when resets recur
Monitor truncation rates to detect upstream instability

When it happens

Trigger: After a successful client.Do, reading the body fails with io.ErrUnexpectedEOF, connection reset by peer, or similar — server/proxy killed the connection before the full body arrived, on every retry.

Common situations: Unstable upstream or CDN dropping large responses; middlebox truncating keep-alive connections; server under load closing connections early; VPN/proxy link flapping.

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/7e12f685321e7ee0. Report an issue: GitHub.

Appendix: source

Thrown at plugin/pan666/pan666.go:219

	// 重试逻辑
	for i := 0; i <= p.retries; i++ {
		// 发送请求
		resp, err = client.Do(req)
		if err != nil {
			if i == p.retries {
				return nil, false, fmt.Errorf("请求失败: %w", err)
			}
			time.Sleep(500 * time.Millisecond)
			continue
		}
		
		defer resp.Body.Close()
		
		// 读取响应体
		responseBody, err = io.ReadAll(resp.Body)
		if err != nil {
			if i == p.retries {
				return nil, false, fmt.Errorf("读取响应失败: %w", err)
			}
			time.Sleep(500 * time.Millisecond)
			continue
		}
		
		// 状态码检查
		if resp.StatusCode != http.StatusOK {
			if i == p.retries {
				return nil, false, fmt.Errorf("API返回非200状态码: %d", resp.StatusCode)
			}
			time.Sleep(500 * time.Millisecond)
			continue
		}
		
		// 请求成功，跳出重试循环
		break
	}

View on GitHub (pinned to beaa561337)