protoc生成go文件报错protoc-gen-go: unable to determine Go import path for

最近在学习rpc，protoc生成go文件时遇到报错。

例子所用的proto文件如下：

syntax = "proto3";
 
package geecachepb;
 
message Request {
  string group = 1;
  string key = 2;
}
 
message Response {
  bytes value = 1;
}
 
service GroupCache {
  rpc Get(Request) returns (Response);
}

运行protoc命令时报错如下：

根据报错信息，解决方案如下：

syntax = "proto3";
 
package geecachepb;
option go_package = "./"; // 指定生成的go文件所在path
 
message Request {
  string group = 1;
  string key = 2;
}
 
message Response {
  bytes value = 1;
}
 
service GroupCache {
  rpc Get(Request) returns (Response);
}

再次运行protoc命令，成功：

对应的pb.go文件如下：

// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
//      protoc-gen-go v1.26.0
//      protoc        v3.19.4
// source: geecachepb.proto
 
package __
 
import (
        protoreflect "google.golang.org/protobuf/reflect/protoreflect"
        protoimpl "google.golang.org/protobuf/runtime/protoimpl"
        reflect "reflect"
        sync "sync"
)
 
const (
        // Verify that this generated code is sufficiently up-to-date.
        _ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
        // Verify that runtime/protoimpl is sufficiently up-to-date.
        _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)
 
type Request struct {
        state         protoimpl.MessageState
        sizeCache     protoimpl.SizeCache
        unknownFields protoimpl.UnknownFields
 
        Group string `protobuf:"bytes,1,opt,name=group,proto3" json:"group,omitempty"`
        Key   string `protobuf:"bytes,2,opt,name=key,proto3" json:"key,omitempty"`
}
 
func (x *Request) Reset() {
        *x = Request{}
        if protoimpl.UnsafeEnabled {
                mi := &file_geecachepb_proto_msgTypes[0]
                ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
                ms.StoreMessageInfo(mi)
        }
}
 
func (x *Request) String() string {
        return protoimpl.X.MessageStringOf(x)
}
 
func (*Request) ProtoMessage() {}
 
func (x *Request) ProtoReflect() protoreflect.Message {
        mi := &file_geecachepb_proto_msgTypes[0]
        if protoimpl.UnsafeEnabled && x != nil {
                ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
                if ms.LoadMessageInfo() == nil {
                        ms.StoreMessageInfo(mi)
                }
                return ms
        }
        return mi.MessageOf(x)
}
 
// Deprecated: Use Request.ProtoReflect.Descriptor instead.
func (*Request) Descriptor() ([]byte, []int) {
        return file_geecachepb_proto_rawDescGZIP(), []int{0}
}
 
func (x *Request) GetGroup() string {
        if x != nil {
                return x.Group
        }
        return ""
}
 
func (x *Request) GetKey() string {
        if x != nil {
                return x.Key
        }
        return ""
}
 
type Response struct {
        state         protoimpl.MessageState
        sizeCache     protoimpl.SizeCache
        unknownFields protoimpl.UnknownFields
 
        Value []byte `protobuf:"bytes,1,opt,name=value,proto3" json:"value,omitempty"`
}
 
func (x *Response) Reset() {
        *x = Response{}
        if protoimpl.UnsafeEnabled {
                mi := &file_geecachepb_proto_msgTypes[1]
                ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
                ms.StoreMessageInfo(mi)
        }
}
 
func (x *Response) String() string {
        return protoimpl.X.MessageStringOf(x)
}
 
func (*Response) ProtoMessage() {}
 
func (x *Response) ProtoReflect() protoreflect.Message {
        mi := &file_geecachepb_proto_msgTypes[1]
        if protoimpl.UnsafeEnabled && x != nil {
                ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
                if ms.LoadMessageInfo() == nil {
                        ms.StoreMessageInfo(mi)
                }
                return ms
        }
        return mi.MessageOf(x)
}
 
// Deprecated: Use Response.ProtoReflect.Descriptor instead.
func (*Response) Descriptor() ([]byte, []int) {
        return file_geecachepb_proto_rawDescGZIP(), []int{1}
}
 
func (x *Response) GetValue() []byte {
        if x != nil {
                return x.Value
        }
        return nil
}
 
var File_geecachepb_proto protoreflect.FileDescriptor
 
var file_geecachepb_proto_rawDesc = []byte{
        0x0a, 0x10, 0x67, 0x65, 0x65, 0x63, 0x61, 0x63, 0x68, 0x65, 0x70, 0x62, 0x2e, 0x70, 0x72, 0x6f,
        0x74, 0x6f, 0x12, 0x0a, 0x67, 0x65, 0x65, 0x63, 0x61, 0x63, 0x68, 0x65, 0x70, 0x62, 0x22, 0x31,
        0x0a, 0x07, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x12, 0x14, 0x0a, 0x05, 0x67, 0x72, 0x6f,
        0x75, 0x70, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x05, 0x67, 0x72, 0x6f, 0x75, 0x70, 0x12,
        0x10, 0x0a, 0x03, 0x6b, 0x65, 0x79, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x03, 0x6b, 0x65,
        0x79, 0x22, 0x20, 0x0a, 0x08, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x12, 0x14, 0x0a,
        0x05, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0c, 0x52, 0x05, 0x76, 0x61,
        0x6c, 0x75, 0x65, 0x32, 0x3e, 0x0a, 0x0a, 0x47, 0x72, 0x6f, 0x75, 0x70, 0x43, 0x61, 0x63, 0x68,
        0x65, 0x12, 0x30, 0x0a, 0x03, 0x47, 0x65, 0x74, 0x12, 0x13, 0x2e, 0x67, 0x65, 0x65, 0x63, 0x61,
        0x63, 0x68, 0x65, 0x70, 0x62, 0x2e, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x14, 0x2e,
        0x67, 0x65, 0x65, 0x63, 0x61, 0x63, 0x68, 0x65, 0x70, 0x62, 0x2e, 0x52, 0x65, 0x73, 0x70, 0x6f,
        0x6e, 0x73, 0x65, 0x42, 0x04, 0x5a, 0x02, 0x2e, 0x2f, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f,
        0x33,
}
 
var (
        file_geecachepb_proto_rawDescOnce sync.Once
        file_geecachepb_proto_rawDescData = file_geecachepb_proto_rawDesc
)
 
func file_geecachepb_proto_rawDescGZIP() []byte {
        file_geecachepb_proto_rawDescOnce.Do(func() {
                file_geecachepb_proto_rawDescData = protoimpl.X.CompressGZIP(file_geecachepb_proto_rawDescData)
        })
        return file_geecachepb_proto_rawDescData
}
 
var file_geecachepb_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
var file_geecachepb_proto_goTypes = []interface{}{
        (*Request)(nil),  // 0: geecachepb.Request
        (*Response)(nil), // 1: geecachepb.Response
}
var file_geecachepb_proto_depIdxs = []int32{
        0, // 0: geecachepb.GroupCache.Get:input_type -> geecachepb.Request
        1, // 1: geecachepb.GroupCache.Get:output_type -> geecachepb.Response
        1, // [1:2] is the sub-list for method output_type
        0, // [0:1] is the sub-list for method input_type
        0, // [0:0] is the sub-list for extension type_name
        0, // [0:0] is the sub-list for extension extendee
        0, // [0:0] is the sub-list for field type_name
}
 
func init() { file_geecachepb_proto_init() }
func file_geecachepb_proto_init() {
        if File_geecachepb_proto != nil {
                return
        }
        if !protoimpl.UnsafeEnabled {
                file_geecachepb_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
                        switch v := v.(*Request); i {
                        case 0:
                                return &v.state
                        case 1:
                                return &v.sizeCache
                        case 2:
                                return &v.unknownFields
                        default:
                                return nil
                        }
                }
                file_geecachepb_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
                        switch v := v.(*Response); i {
                        case 0:
                                return &v.state
                        case 1:
                                return &v.sizeCache
                        case 2:
                                return &v.unknownFields
                        default:
                                return nil
                        }
                }
        }
        type x struct{}
        out := protoimpl.TypeBuilder{
                File: protoimpl.DescBuilder{
                        GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
                        RawDescriptor: file_geecachepb_proto_rawDesc,
                        NumEnums:      0,
                        NumMessages:   2,
                        NumExtensions: 0,
                        NumServices:   1,
                },
                GoTypes:           file_geecachepb_proto_goTypes,
                DependencyIndexes: file_geecachepb_proto_depIdxs,
                MessageInfos:      file_geecachepb_proto_msgTypes,
        }.Build()
        File_geecachepb_proto = out.File
        file_geecachepb_proto_rawDesc = nil
        file_geecachepb_proto_goTypes = nil
        file_geecachepb_proto_depIdxs = nil
}

参考文档：go语言protoc编译问题-protoc-gen-go: unable to determine Go import path for “searchnode.proto“