proto: use v2 of Protobuf

[mewmew]

The CI system has not yet been update to download
the needed tools for protobuf v2 generation, these
are:

go get -u google.golang.org/protobuf/cmd/protoc-gen-go
go get -u google.golang.org/protobuf/cmd/protoc-gen-go-grpc

Note: protoc-gen-go-grpc will move to google.golang.org/grpc
in the future (see golang/protobuf#903).

Tentative fix of #10.

[mewmew]

Looks like protobuf v2 is not yet ready for prime time:

After clicking on bin ID dea24b0f72a7447f8eb7145c8d13e0a6c2783679c24c130329bbffefbd960864, the resulting panic is encountered on the backend.

Backend output:

strings-go.1     | pi-strings-go: parsing ID "dea24b0f72a7447f8eb7145c8d13e0a6c2783679c24c130329bbffefbd960864"
disasm-objdump.1 | panic: protobuf tag not enough fields in InstAddrsRequest.state: 
disasm-objdump.1 | 
disasm-objdump.1 | goroutine 25 [running]:
disasm-objdump.1 | github.com/golang/protobuf/proto.(*unmarshalInfo).computeUnmarshalInfo(0xc00011a780)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/github.com/golang/[email protected]/proto/table_unmarshal.go:332 +0x16a3
disasm-objdump.1 | github.com/golang/protobuf/proto.(*unmarshalInfo).unmarshal(0xc00011a780, 0xc000086ac0, 0xc000106280, 0x42, 0x42, 0x40e168, 0x20)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/github.com/golang/[email protected]/proto/table_unmarshal.go:136 +0xde0
disasm-objdump.1 | github.com/golang/protobuf/proto.(*InternalMessageInfo).Unmarshal(0xc0000aa9a0, 0x7ff7d5b4f298, 0xc000086ac0, 0xc000106280, 0x42, 0x42, 0x2, 0x0)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/github.com/golang/[email protected]/proto/table_unmarshal.go:63 +0x66
disasm-objdump.1 | github.com/golang/protobuf/proto.(*Buffer).Unmarshal(0xc00011cae8, 0x7ff7d5b4f298, 0xc000086ac0, 0x0, 0x0)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/github.com/golang/[email protected]/proto/decode.go:424 +0x1ec
disasm-objdump.1 | google.golang.org/grpc/encoding/proto.codec.Unmarshal(0xc000106280, 0x42, 0x42, 0x99af60, 0xc000086ac0, 0xc000050900, 0x7ff7d5b4f270)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/encoding/proto/proto.go:93 +0x12e
disasm-objdump.1 | google.golang.org/grpc.(*Server).processUnaryRPC.func4(0x99af60, 0xc000086ac0, 0x30, 0x9bfb00)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/server.go:976 +0xcc
disasm-objdump.1 | github.com/lapsang-boys/pippi/proto/disasm_objdump._InstAddrExtractor_ExtractInstAddrs_Handler(0x95a880, 0xea9620, 0xad36e0, 0xc00011cab0, 0xc0000b6a00, 0x0, 0xad36e0, 0xc00011cab0, 0xc000106280, 0x42)
disasm-objdump.1 | 	/home/u/Desktop/pippi/proto/disasm_objdump/disasm_objdump_grpc.pb.go:53 +0x53
disasm-objdump.1 | google.golang.org/grpc.(*Server).processUnaryRPC(0xc00008c780, 0xad8e00, 0xc00008c900, 0xc00019c000, 0xc00011c6f0, 0xe7a7e0, 0x0, 0x0, 0x0)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/server.go:998 +0x46a
disasm-objdump.1 | google.golang.org/grpc.(*Server).handleStream(0xc00008c780, 0xad8e00, 0xc00008c900, 0xc00019c000, 0x0)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/server.go:1278 +0xd97
disasm-objdump.1 | google.golang.org/grpc.(*Server).serveStreams.func1.1(0xc0000a0b10, 0xc00008c780, 0xad8e00, 0xc00008c900, 0xc00019c000)
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/server.go:717 +0xbb
disasm-objdump.1 | created by google.golang.org/grpc.(*Server).serveStreams.func1
disasm-objdump.1 | 	/home/u/goget/pkg/mod/google.golang.org/[email protected]/server.go:715 +0xa1

Frontend output:

2019/10/09 01:08:55 rpc error: code = Unavailable desc = transport is closing
2019/10/09 01:08:55 rpc error: code = Unavailable desc = transport is closing

[mewmew]

Let's revisit this one protobuf v2 matures a bit; tracked upstream by the protobuf v2 release milestone.

[karlek]

Sounds good! There's a limit to how much a man can bleed