nordisk/dwarves

crates/dwarves-web-client/build.rs

// build.rs — compile this crate's OWN `proto/dwarf.proto` into a prost + tonic CLIENT.
//
// ── WHY A THIRD COPY, AND NOT `../dwarves-embed/proto` ─────────────────────────
//
// Until 2026-08-24 this file read the sibling's copy directly:
//
//     let proto = "../dwarves-embed/proto/dwarf.proto";
//
// which is REUSE inside the checkout and a BROKEN CRATE on crates.io. `cargo package`
// only ever puts files from UNDER the package root into the tarball, so `../` resolves
// outside the extracted crate and simply is not there. MEASURED — `cargo package` on
// `dwarves-web-client 0.1.4` in a standalone workspace:
//
//     thread 'main' panicked at build.rs:17:53:
//     protox: compile dwarf.proto: file '../dwarves-embed/proto/dwarf.proto'
//                                  is not in any include path
//     error: failed to verify package tarball
//
// The `publish = true` flag came off on 2026-08-23 (4425148) and this is why the crate
// never actually went up: nothing about it is wrong INSIDE the workspace, and nothing
// about it works outside one. That is the whole shape of a publish defect — it can only
// be seen from where the consumer stands, and after an irreversible upload it is too
// late to see it at all.
//
// So the crate owns its proto, exactly as `dwarves` and `dwarves-embed` already own
// theirs. dwarf.proto now has THREE hand-maintained copies and the byte-for-byte
// agreement of this one with the embed copy is not a comment, it is
// `dwarves-embed/tests/proto_parity.rs` — protobuf decodes by NUMBER, so a field that
// drifts here does not error, it lands in the wrong slot on a live `dwarves-server`.
//
// Pure-Rust codegen (the nordisk zero-shell charter): `protox` (a pure-Rust .proto
// parser) produces the FileDescriptorSet, then `tonic-build` emits the client bindings
// from it — no `protoc` binary, no C. Mirrors `crates/dwarves-embed/build.rs`.

fn main() {
    println!("cargo:rerun-if-changed=proto/dwarf.proto");
    println!("cargo:rerun-if-changed=build.rs");

    let fds =
        protox::compile(["proto/dwarf.proto"], ["proto"]).expect("protox: compile dwarf.proto");

    tonic_prost_build::configure()
        .build_server(false)
        .build_client(true)
        // ── NO tonic `Channel` CONSTRUCTOR ────────────────────────────────────────
        //
        // `build_transport(true)` (the default) makes tonic-prost-build emit an
        // UNGATED `impl DwarfClient<tonic::transport::Channel>` carrying the `connect`
        // convenience constructor. This crate declares
        // `tonic = { default-features = false, features = ["codegen"] }` — no
        // `channel`, deliberately — because it is the BROWSER client: it dials through
        // `tonic_web_wasm_client::Client` over `fetch`, and tonic's native transport
        // (hyper + tokio sockets) neither compiles to wasm nor is ever wanted here.
        //
        // Inside the dwarves workspace that mismatch was INVISIBLE: `dwarves-embed`
        // declares `tonic = { features = ["transport", "codegen"] }`, and cargo's
        // feature UNIFICATION handed the same tonic build to this crate, so the
        // generated `connect` always found its `Channel`. Standalone — i.e. as a
        // consumer of the published crate sees it — it does not:
        //
        //     error[E0433]: cannot find `transport` in `tonic`
        //       --> OUT_DIR/dwarf.v1.rs:177:29
        //     note: found an item that was configured out
        //       --> tonic-0.14.6/src/lib.rs:110:9  `#[cfg(any(feature = "server",
        //                                            feature = "channel"))] pub mod transport;`
        //     error: could not compile `dwarves-web-client` (lib) due to 4 previous errors
        //
        // MEASURED 2026-08-24 via `cargo package` in a standalone workspace. The fix is
        // NOT to add tonic's `channel` feature — that would drag a native socket stack
        // into the wasm bundle and break the wasm target instead. The constructor is
        // simply not part of this client's surface, so it is not generated.
        .build_transport(false)
        .compile_fds(fds)
        .expect("tonic-build: codegen");
}