Generate invalid timestamp code

generate.sh

# Install protoc3. Left as exercise to reader

# Install protoc-gen-gogo and friends
go get github.com/gogo/protobuf/proto
go get github.com/gogo/protobuf/jsonpb
go get github.com/gogo/protobuf/protoc-gen-gogo
go get github.com/gogo/protobuf/gogoproto

# Generate file
protoc my.proto --gogo_out=Mgoogle/protobuf/timestamp.proto=github.com/gogo/protobuf/types:./ -I./ -I$GOPATH/src

my.pb.go

// Code generated by protoc-gen-gogo.
// source: my.proto
// DO NOT EDIT!

/*
Package my is a generated protocol buffer package.

It is generated from these files:
	my.proto

It has these top-level messages:
	Value
*/
package my

import proto "github.com/gogo/protobuf/proto"
import fmt "fmt"
import math "math"
import google_protobuf "github.com/gogo/protobuf/types"
import _ "github.com/gogo/protobuf/gogoproto"

import time "time"

// Reference imports to suppress errors if they are not otherwise used.
var _ = proto.Marshal
var _ = fmt.Errorf
var _ = math.Inf

// This is a compile-time assertion to ensure that this generated file
// is compatible with the proto package it is being compiled against.
// A compilation error at this line likely means your copy of the
// proto package needs to be updated.
const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package

type Value struct {
	Time *time.Time `protobuf:"bytes,1,opt,name=time,stdtime" json:"time,omitempty"`
}

func (m *Value) Reset()                    { *m = Value{} }
func (m *Value) String() string            { return proto.CompactTextString(m) }
func (*Value) ProtoMessage()               {}
func (*Value) Descriptor() ([]byte, []int) { return fileDescriptorMy, []int{0} }

func (m *Value) GetTime() *time.Time {
	if m != nil {
		return m.Time
	}
	return nil
}

func init() {
	proto.RegisterType((*Value)(nil), "my.Value")
}

func init() { proto.RegisterFile("my.proto", fileDescriptorMy) }

var fileDescriptorMy = []byte{
	// 138 bytes of a gzipped FileDescriptorProto
	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0xe2, 0xe2, 0xc8, 0xad, 0xd4, 0x2b,
	0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0xca, 0xad, 0x94, 0x92, 0x4f, 0xcf, 0xcf, 0x4f, 0xcf, 0x49,
	0xd5, 0x07, 0x8b, 0x24, 0x95, 0xa6, 0xe9, 0x97, 0x64, 0xe6, 0xa6, 0x16, 0x97, 0x24, 0xe6, 0x16,
	0x40, 0x14, 0x49, 0xe9, 0xa6, 0x67, 0x96, 0x64, 0x94, 0x26, 0xe9, 0x25, 0xe7, 0xe7, 0xea, 0xa7,
	0xe7, 0xa7, 0xe7, 0x23, 0x54, 0x82, 0x78, 0x60, 0x0e, 0x98, 0x05, 0x51, 0xae, 0x64, 0xcb, 0xc5,
	0x1a, 0x96, 0x98, 0x53, 0x9a, 0x2a, 0x64, 0xc2, 0xc5, 0x02, 0x32, 0x4a, 0x82, 0x51, 0x81, 0x51,
	0x83, 0xdb, 0x48, 0x4a, 0x0f, 0x62, 0x8f, 0x1e, 0x4c, 0xb7, 0x5e, 0x08, 0xcc, 0x1e, 0x27, 0x96,
	0x09, 0xf7, 0xe5, 0x19, 0x83, 0xc0, 0xaa, 0x93, 0xd8, 0xc0, 0xf2, 0xc6, 0x80, 0x00, 0x00, 0x00,
	0xff, 0xff, 0x1a, 0xf9, 0xe3, 0x04, 0xa5, 0x00, 0x00, 0x00,
}

my.proto

syntax = "proto3";

package my;

import "google/protobuf/timestamp.proto";
import "github.com/gogo/protobuf/gogoproto/gogo.proto";

message Value {
    google.protobuf.Timestamp time = 1 [(gogoproto.stdtime) = true];
}