Protobuf bytes field incorrectly parsed as String when generating gRPC code with tonic_build

[starcorn2020]

Bug Report

Version

➜ proto_tools cargo tree | grep tonic
├── tonic v0.12.1
└── tonic-build v0.12.1

Platform

Linux ip-xxxxxxxxx-aws #61~20.04.1-Ubuntu SMP Wed Mar 13 17:40:41 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

Description

Encountered Issue: bytes field generated as String

// Header defines the structure of a block header.
message Header {
// basic block info
tendermint.version.Consensus version = 1 [(gogoproto.nullable) = false];
string chain_id = 2 [(gogoproto.customname) = "ChainID"];
int64 height = 3;
google.protobuf.Timestamp time = 4 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true];

// prev block info
BlockID last_block_id = 5 [(gogoproto.nullable) = false];

// hashes of block data
bytes last_commit_hash = 6; // commit from validators from the last block
bytes data_hash = 7; // transactions

// hashes from the app output from the prev block
bytes validators_hash = 8; // validators for the current block
bytes next_validators_hash = 9; // validators for the next block
bytes consensus_hash = 10; // consensus params for current block
bytes app_hash = 11; // state after txs from the previous block
bytes last_results_hash = 12; // root hash of all results from the txs from the previous block

// consensus info
bytes evidence_hash = 13; // evidence included in the block
bytes proposer_address = 14; // original proposer of the block
}

And the generated code is as follows:

#[allow(clippy::derive_partial_eq_without_eq)]
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct Header {
/// basic block info
#[prost(message, optional, tag = "1")]
pub version: ::core::option::Optionsuper::super::super::super::tendermint::version::Consensus,
#[prost(string, tag = "2")]
pub chain_id: ::prost::alloc::string::String,
#[prost(int64, tag = "3")]
pub height: i64,
#[prost(message, optional, tag = "4")]
pub time: ::core::option::Option<::prost_types::Timestamp>,
/// prev block info
#[prost(message, optional, tag = "5")]
pub last_block_id:
::core::option::Optionsuper::super::super::super::tendermint::types::BlockId,
/// hashes of block data
///
/// commit from validators from the last block
#[prost(bytes = "vec", tag = "6")]
pub last_commit_hash: ::prost::alloc::vec::Vec,
/// transactions
#[prost(bytes = "vec", tag = "7")]
pub data_hash: ::prost::alloc::vec::Vec,
/// hashes from the app output from the prev block
///
/// validators for the current block
#[prost(bytes = "vec", tag = "8")]
pub validators_hash: ::prost::alloc::vec::Vec,
/// validators for the next block
#[prost(bytes = "vec", tag = "9")]
pub next_validators_hash: ::prost::alloc::vec::Vec,
/// consensus params for current block
#[prost(bytes = "vec", tag = "10")]
pub consensus_hash: ::prost::alloc::vec::Vec,
/// state after txs from the previous block
#[prost(bytes = "vec", tag = "11")]
pub app_hash: ::prost::alloc::vec::Vec,
/// root hash of all results from the txs from the previous block
#[prost(bytes = "vec", tag = "12")]
pub last_results_hash: ::prost::alloc::vec::Vec,
/// consensus info
///
/// evidence included in the block
#[prost(bytes = "vec", tag = "13")]
pub evidence_hash: ::prost::alloc::vec::Vec,
/// proposer_address is the original block proposer address, formatted as a Bech32 string.
/// In Tendermint, this type is bytes, but in the SDK, we convert it to a Bech32 string
/// for better UX.
///
/// original proposer of the block
#[prost(string, tag = "14")]
pub proposer_address: ::prost::alloc::string::String,
}

As you can see, proposer_address is generated as a String instead of the original bytes type defined in the Proto. In practice, I encountered this issue where it seems like the gRPC message field should be bytes, but tonic is unable to correctly parse it as bytes.

"message": "Failed to get latest block: Status { code: Internal, message: "failed to decode Protobuf message: Header.proposer_address: Block.header: GetLatestBlockResponse.block: invalid string value: data is not UTF-8 encoded", metadata: MetadataMap { headers: {"date": "Sat, 24 Aug 2024 02:53:52 GMT", "content-type": "application/grpc", "strict-transport-security": "max-age=31536000; includeSubDomains; preload", "x-cosmos-block-height": "23542656", "x-envoy-upstream-service-time": "479", "cf-cache-status": "DYNAMIC", "x-content-type-options": "nosniff", "server": "cloudflare", "cf-ray": "8b800dec6f9de011-NRT", "alt-svc": "h3=\":443\"; ma=86400"} }, source: None }"

[starcorn2020]

I found that it was caused by incorrect compilation settings. Closing the issue.