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# gRPC的Go实现，其返回的error为什么不用fmt.Errorf()？

比如你要返回一个gorm.ErrRecordNotFound，那么gRPC的调用者最终收到的error的信息会是这样：

```
rpc error: code = Unknown desc = 
```

调用者想这么判断error：

```
if errors.Is(err, gorm.ErrRecordNotFound)
```

会返回false

用errors.As也不行

```
errors.As(err, &gorm.ErrRecordNotFound)
```

在运行测试的时候会报错：second argument to errors.As should not be \*error

GPT的解释：The error message you're seeing is because errors.As expects a pointer to an interface as its second argument. However, gorm.ErrRecordNotFound is a value of type error, not an interface type.

{% embed url="<https://github.com/grpc/grpc-go/issues/2934>" %}