go build_error ai_generated true

panic: proto: duplicate field number 5 in message pb.User

ID: go/protobuf-duplicate-field-number

Also available as: JSON · Markdown · 中文
80%Fix Rate
89%Confidence
0Evidence
2025-01-09First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.x active — — —

Root Cause

Two fields in the same message share a field number, which protobuf forbids. This usually arises from hand-editing generated code or merging conflicting .proto definitions.

generic

中文

同一消息中的两个字段共享相同的字段编号，protobuf 禁止此行为。通常由手工编辑生成代码或合并冲突的 .proto 定义引起。

Workarounds

  1. 95% success 
    Assign a unique field number to each field in the .proto, then regenerate with protoc --go_out=. --go-grpc_out=. and never hand-edit generated files.
  2. 90% success 
    Use reserved field numbers to prevent reuse: reserved 5; when removing a field, and run buf lint to catch duplicate numbers at build time.

Dead Ends

Common approaches that don't work:

  1. 95% fail

    The duplicate numbering corrupts wire format; removing the check produces silent data corruption instead of a clear failure.

  2. 90% fail

    The number, not the name, is what must be unique; the panic persists.