error in generated code after importing shared proto

[maartensson]

I would like to be able to import a protofile into another.

Compiling and accessing the members of each protocol separately works fine, but they cannot access each other in the generated code as this error message shows:

Error[E0433]: failed to resolve: could not find `shared` in the crate root
  --> /home/martin/dk-slack/website/target/debug/build/eventsservice-b3f9e3601151fe7f/out/user.rs:90:43
   |
90 |             tonic::Response<super::super::shared::EventList>,
   |                                           ^^^^^^ could not find `shared` in the crate root

error[E0433]: failed to resolve: could not find `shared` in the crate root
   --> /home/martin/dk-slack/website/target/debug/build/userservice-622161de9a99e87b/out/registration.rs:203:60
    |
203 |             request: impl tonic::IntoRequest<super::super::shared::UserInformation>,
    |                                                            ^^^^^^ could not find `shared` in the crate root
error[E0283]: type annotations needed for `ProstCodec<(), U>`
   --> /home/martin/dk-slack/website/target/debug/build/eventsservice-b3f9e3601151fe7f/out/user.rs:102:17
    |
102 |             let codec = tonic::codec::ProstCodec::default();
    |                 ^^^^^
...
106 |             self.inner.unary(req, path, codec).await
    |                        ----- type must be known at this point
    |
    = note: cannot satisfy `_: Message`
    = help: the following types implement trait `Message`:
              bool
              i32
              i64
              u32
              u64
              f32
              f64
              EventList
            and 55 others
    = note: required for `ProstCodec<(), _>` to implement `Codec`
note: required by a bound in `tonic::client::Grpc::<T>::unary`
   --> /home/martin/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tonic-0.10.2/src/client/grpc.rs:215:12
    |
205 |     pub async fn unary<M1, M2, C>(
    |                  ----- required by a bound in this associated function
...
215 |         C: Codec<Encode = M1, Decode = M2>,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Grpc::<T>::unary`
help: consider giving `codec` an explicit type, where the type for type parameter `U` is specified
    |
102 |             let codec: ProstCodec<(), U> = tonic::codec::ProstCodec::default();
    |                      +++++++++++++++++++

Some errors have detailed explanations: E0283, E0433.
For more information about an error, try `rustc --explain E0283`.
For more information about this error, try `rustc --explain E0433`.
error: could not compile `eventsservice` (lib) due to 2 previous errors

❯ cd target/debug/build/eventsservice-b3f9e3601151fe7f
❯ tree
.
├── invoked.timestamp
├── out
│   ├── shared.rs
│   └── user.rs
├── output
├── root-output
└── stderr

My project

.
├── eventsservice
│   ├── build.rs
│   ├── Cargo.toml
│   └── src
│       └── lib.rs
└── protos
      └── events_service
              ├── shared.proto
              └── user.proto

// ../protos/events_service/user.proto
syntax = "proto3";

import "google/protobuf/empty.proto";
import "shared.proto";

package user;

option go_package = "github.com/dk-slack/protos/events_service/golang/user";

service Events {
  rpc List ( google.protobuf.Empty ) returns ( shared.EventList );
}

// ../protos/events_service/shared.proto
syntax = "proto3";

package shared;

option go_package = "github.com/dk-slack/protos/events_service/golang/shared";

message EventList {
  repeated shared.Event events = 1;
}

message Event {
  enum EventType {
    WEEKLYMEETING = 0;
    WATERLINE = 1;
    HIGHLINE = 2;
    MEETING = 3;
    WORKSHOP = 4;
    AUDIT = 5;
    RIGGING = 6;
  }

  message Location {
    message Coordinates {
      float lng = 1;
      float lat = 2;
    }
    string name = 1;
    Coordinates coordinates = 2;
  }

  string title = 1;
  Location location = 2;
  EventType event_type = 3;
  uint64 time = 4;
}

// build.rs
fn main() -> Result<(), Box<dyn std::error::Error>> {
    tonic_build::configure().build_server(false).compile(
        &[
            "../protos/events_service/user.proto",
            "../protos/events_service/shared.proto",
        ],
        &["../protos/events_service"],
    )?;
    Ok(())
}

// src/lib.rs
mod events {
    tonic::include_proto!("user");
}

mod proto_shared {
    tonic::include_proto!("shared");
}

use proto_shared::event::EventType as ET;

use tonic::transport::Channel;

pub use shared::errors::UserEventError;

#[derive(Clone)]
pub struct UserEventsClient {
    cli: events::events_client::EventsClient<Channel>,
}

impl UserEventsClient {
    pub async fn new() -> Result<Self, UserEventError> {
        Ok(Self {
            cli: events::events_client::EventsClient::connect("http://localhost:50057")
                .await
                .map_err(|_| UserEventError::ConnectionError)?,
        })
    }
}

I had similar issues in golang when importing a package because I was using relative package names imports and go doesn't allow that in modules. So I was forced to specify a fully qualified package name in the option go_package and make a library that my other go modules could then import the grpc functionality from.

[maartensson]

Never mind I just realized that I have to give the module the same name as the package name in the protofile.

I was calling it proto_shared instead of shared.