# 恐慌：关闭nil通道

- **ID:** `go/goroutine-close-nil-channel`
- **领域:** go
- **类别:** runtime_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

对nil通道调用close()，这是编程错误。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.0 | active | — | — |
| 1.21 | active | — | — |

## 解决方案

1. **Initialize channel before close** (99% 成功率)
   ```
   ch := make(chan int)
// use ch
close(ch)
   ```
2. **Use sync.Once to safely close only if initialized** (85% 成功率)
   ```
   var once sync.Once
if ch != nil {
    once.Do(func() { close(ch) })
}
   ```

## 无效尝试

- **Using recover() to catch panic** — Recover works but doesn't fix the logic; channel remains nil. (90% 失败率)
- **Checking ch != nil before close but not initializing** — Nil check prevents panic but channel is never initialized; subsequent operations fail. (80% 失败率)