go runtime_error ai_generated true

panic: runtime error: invalid memory address or nil pointer dereference

ID: go/proto-nil-pointer-deref-proto-message

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-04-18First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
google.golang.org/protobuf 1.x active — — —

Root Cause

A nil *pb.Message was dereferenced, typically from a nil nested message field or a nil response returned alongside an error. In protobuf Go, reading a nil message field returns nil, and calling a getter on nil is safe but direct field access is not.

generic

中文

解引用了一个 nil 的 *pb.Message，通常来自 nil 的嵌套消息字段，或与错误一起返回的 nil 响应。在 protobuf Go 中，读取 nil 消息字段返回 nil，对 nil 调用 getter 是安全的，但直接字段访问则不是。

Workarounds

  1. 92% success 
    Always check the error before touching the response, and use generated getters which are nil-safe:

resp, err := client.GetUser(ctx, req)
if err != nil { return err }
name := resp.GetUser().GetName() // getters return zero values on nil
  2. 85% success 
    Initialize nested messages explicitly before writing to them:

if resp.User == nil { resp.User = &pb.User{} }
resp.User.Name = "alice"

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Recovering hides the bug and leaves the program in an inconsistent state; the nil is a logic error that must be fixed at the source.

  2. 70% fail

    The nil is often in a nested field (e.g. resp.User.Address); checking only the outer message still panics on the inner access.