go build_error ai_generated true

protoc-gen-go: error: duplicate symbol "pb.User" in file "user.proto" and "user_v2.proto"

ID: go/proto-duplicate-symbol

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
0Evidence
2024-08-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
protoc-gen-go 1.31+ active — — —

Root Cause

Two .proto files declare the same fully-qualified message name (same package + message) and are compiled together, causing a symbol collision in generated Go code.

generic

中文

两个 .proto 文件声明了相同的完全限定消息名（相同 package + message）并被一起编译，导致生成的 Go 代码中符号冲突。

Workarounds

  1. 95% success 
    Give each file a distinct proto package:
// user.proto
package pb.v1;
// user_v2.proto
package pb.v2;
  2. 85% success 
    Use buf to detect and lint duplicate symbols across the workspace:
buf lint
buf breaking --against '.git#branch=main'

Dead Ends

Common approaches that don't work:

  1. 90% fail

    The collision is on the protobuf fully-qualified name, not the Go package; protoc still errors.

  2. 85% fail

    At link time the generated Go files still declare identical Go types and the Go build fails.