# go: example.com/module@v1.0.0：读取 https://proxy.golang.org/example.com/module/@v/v1.0.0.mod：拨号 tcp：查找 proxy.golang.org：I/O 超时

- **ID:** `go/proxy-connectivity-timeout`
- **领域:** go
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

无法连接到 Go 模块代理网络，通常是由于防火墙限制、DNS 问题或代理宕机。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.11 | active | — | — |
| 1.12 | active | — | — |
| 1.13 | active | — | — |
| 1.14 | active | — | — |
| 1.15 | active | — | — |
| 1.16 | active | — | — |
| 1.17 | active | — | — |
| 1.18 | active | — | — |
| 1.19 | active | — | — |
| 1.20 | active | — | — |
| 1.21 | active | — | — |
| 1.22 | active | — | — |
| 1.23 | active | — | — |

## 解决方案

1. **Set GOPROXY=off to bypass proxy and fetch directly from VCS** (70% 成功率)
   ```
   export GOPROXY=off && go mod download
   ```
2. **Use a different proxy or direct connection** (80% 成功率)
   ```
   export GOPROXY=https://goproxy.io,direct && go mod download
   ```

## 无效尝试

- **Retrying the same command repeatedly** — Network timeout is likely persistent; retrying without fixing connectivity will continue to fail. (90% 失败率)
- **Setting GOPROXY=https://proxy.golang.org,direct** — This is the default; if the proxy is unreachable, it will still timeout before falling back to direct. (50% 失败率)