build.rs

// build.rs
use std::path::Path;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Declare the build_protos cfg flag for cargo check-cfg
    println!("cargo::rustc-check-cfg=cfg(build_protos)");

    // Tell Cargo to rerun this build script if migrations change
    println!("cargo:rerun-if-changed=migrations");
    // Rerun if proto definitions change
    println!("cargo:rerun-if-changed=vendor/snapchain/proto/definitions");

    let proto_dir = "vendor/snapchain/proto/definitions";

    // Only compile protos if the submodule exists (not available in crates.io package)
    // When publishing to crates.io, use the pre-generated src/proto.gen.rs instead
    if Path::new(proto_dir).exists() {
        println!("cargo:rustc-cfg=build_protos");

        tonic_prost_build::configure()
            .type_attribute(".", "#[derive(serde::Serialize, serde::Deserialize)]")
            // Add an attribute to silence large_enum_variant warnings in generated code
            .type_attribute(".", "#[allow(clippy::large_enum_variant)]")
            .build_server(false)
            .compile_protos(
                &[
                    "vendor/snapchain/proto/definitions/admin_rpc.proto",
                    "vendor/snapchain/proto/definitions/blocks.proto",
                    "vendor/snapchain/proto/definitions/gossip.proto",
                    "vendor/snapchain/proto/definitions/hub_event.proto",
                    "vendor/snapchain/proto/definitions/message.proto",
                    "vendor/snapchain/proto/definitions/node_state.proto",
                    "vendor/snapchain/proto/definitions/onchain_event.proto",
                    "vendor/snapchain/proto/definitions/request_response.proto",
                    "vendor/snapchain/proto/definitions/rpc.proto",
                    "vendor/snapchain/proto/definitions/sync_trie.proto",
                    "vendor/snapchain/proto/definitions/username_proof.proto",
                ],
                &[proto_dir],
            )?;
    } else {
        println!("cargo:warning=Proto submodule not found, using pre-generated src/proto.gen.rs");
    }

    Ok(())
}