fix: move proto code generation output to OUT_DIR, out of tree

.github/actions/install-protobuf-compiler/action.yml

@@ -0,0 +1,13 @@
+
+name: "Install protobuf compiler"
+description: "Install compiler for protobuf compilation"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install protobuf compiler
+      shell: bash
+      run: |
+        set -eux
+        sudo apt-get update
+        sudo apt-get install -y protobuf-compiler

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ on:
 
 env:
   # Shared prefix key for the rust cache.
-  # 
+  #
   # This provides a convenient way to evict old or corrupted cache.
   RUST_CACHE_KEY: rust-cache-2026.02.02
   # Reduce cache usage by removing debug information.
@@ -47,8 +47,8 @@ jobs:
       - uses: actions/checkout@v6
       - name: Cleanup large tools for build space
         uses: ./.github/actions/cleanup-runner
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
       - name: Rustup
         run: rustup update --no-self-update
       - uses: Swatinem/rust-cache@v2
@@ -95,7 +95,7 @@ jobs:
             fi
           done
           echo "Static linkage check passed for all of ${bin_targets[@]}"
-  
+
   clippy:
     name: lint - clippy
     runs-on: ubuntu-24.04
@@ -152,29 +152,6 @@ jobs:
       - name: Build docs
         run: cargo doc --no-deps --workspace --all-features --locked
 
-  # Ensures our checked-in protobuf generated code is aligned to the protobuf schema.
-  #
-  # We do this by rebuilding the generated code and ensuring there is no diff.
-  proto:
-    name: gRPC codegen
-    needs: [build]
-    runs-on: ubuntu-24.04
-    steps:
-      - uses: actions/checkout@v6
-      - name: Rustup
-        run: rustup update --no-self-update
-      - name: Install protobuf
-        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler
-      - uses: Swatinem/rust-cache@v2
-        with:
-          shared-key: ${{ github.workflow }}-build
-          prefix-key: ${{ env.RUST_CACHE_KEY }}
-          save-if: false
-      - name: Rebuild protos
-        run: BUILD_PROTO=1 cargo check --all-features --all-targets --locked --workspace
-      - name: Diff check
-        run: git diff --exit-code
-
   # Ensure the stress-test still functions by running some cheap benchmarks.
   stress-test:
     name: stress test
@@ -204,7 +181,7 @@ jobs:
           cargo run --bin miden-node-stress-test seed-store \
             --data-directory ${{ env.DATA_DIR }} \
             --num-accounts 500 --public-accounts-percentage 50
-  # TODO re-introduce 
+  # TODO re-introduce
       # - name: Benchmark state sync
         # run: |
           # cargo run --bin miden-node-stress-test benchmark-store \

.github/workflows/nightly.yml

@@ -23,8 +23,8 @@ jobs:
           ref: "next"
       - name: Cleanup large tools for build space
         uses: ./.github/actions/cleanup-runner
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
       - name: Rustup
         run: rustup install beta && rustup default beta
       - uses: taiki-e/install-action@v2
@@ -45,8 +45,8 @@ jobs:
           ref: "next"
       - name: Cleanup large tools for build space
         uses: ./.github/actions/cleanup-runner
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
       - name: Install rust
         run: rustup update --no-self-update
       - name: Install cargo-hack

.github/workflows/publish-debian-all.yml

@@ -31,8 +31,8 @@ jobs:
         uses: actions/checkout@main
         with:
           fetch-depth: 0
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
       - name: Build and Publish Node
         uses: ./.github/actions/debian
         with:

.github/workflows/publish-debian.yml

@@ -60,8 +60,8 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
 
       - name: Build and Publish Packages
         uses: ./.github/actions/debian

.github/workflows/publish-main.yml

@@ -18,8 +18,8 @@ jobs:
         with:
           fetch-depth: 0
           ref: main
-      - name: Install RocksDB
-        uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-rocksdb
+      - uses: ./.github/actions/install-protobuf-compiler
       # Ensure the release tag refers to the latest commit on main.
       # Compare the commit SHA that triggered the workflow with the HEAD of the branch we just
       # checked out (main).

Makefile

@@ -7,7 +7,6 @@ help:
 # -- variables ------------------------------------------------------------------------------------
 
 WARNINGS=RUSTDOCFLAGS="-D warnings"
-BUILD_PROTO=BUILD_PROTO=1
 CONTAINER_RUNTIME ?= docker
 STRESS_TEST_DATA_DIR ?= stress-test-store-$(shell date +%Y%m%d-%H%M%S)
 
@@ -86,7 +85,7 @@ test:  ## Runs all tests
 
 .PHONY: check
 check: ## Check all targets and features for errors without code generation
-	${BUILD_PROTO} cargo check --all-features --all-targets --locked --workspace
+	cargo check --all-features --all-targets --locked --workspace
 
 .PHONY: check-features
 check-features: ## Checks all feature combinations compile without warnings using cargo-hack
@@ -96,22 +95,22 @@ check-features: ## Checks all feature combinations compile without warnings usin
 
 .PHONY: build
 build: ## Builds all crates and re-builds protobuf bindings for proto crates
-	${BUILD_PROTO} cargo build --locked --workspace
-	${BUILD_PROTO} cargo build --locked -p miden-remote-prover-client --target wasm32-unknown-unknown --no-default-features --features batch-prover,block-prover,tx-prover # no-std compatible build
+	cargo build --locked --workspace
+	cargo build --locked -p miden-remote-prover-client --target wasm32-unknown-unknown --no-default-features --features batch-prover,block-prover,tx-prover # no-std compatible build
 
 # --- installing ----------------------------------------------------------------------------------
 
 .PHONY: install-node
 install-node: ## Installs node
-	${BUILD_PROTO} cargo install --path bin/node --locked
+	cargo install --path bin/node --locked
 
 .PHONY: install-remote-prover
 install-remote-prover: ## Install remote prover's CLI
-	$(BUILD_PROTO) cargo install --path bin/remote-prover --bin miden-remote-prover --locked
+	cargo install --path bin/remote-prover --bin miden-remote-prover --locked
 
 .PHONY: stress-test-smoke
 stress-test: ## Runs stress-test benchmarks
-	${BUILD_PROTO} cargo build --release --locked -p miden-node-stress-test
+	cargo build --release --locked -p miden-node-stress-test
 	@mkdir -p $(STRESS_TEST_DATA_DIR)
 	./target/release/miden-node-stress-test seed-store --data-directory $(STRESS_TEST_DATA_DIR) --num-accounts 500 --public-accounts-percentage 50
 	./target/release/miden-node-stress-test benchmark-store --data-directory $(STRESS_TEST_DATA_DIR) --iterations 10 --concurrency 1 sync-state

bin/remote-prover/Cargo.toml

@@ -46,7 +46,15 @@ miden-testing   = { workspace = true }
 miden-tx        = { features = ["testing"], workspace = true }
 
 [build-dependencies]
+fs-err                             = { workspace = true }
 miden-node-proto-build             = { features = ["internal"], workspace = true }
 miden-node-rocksdb-cxx-linkage-fix = { workspace = true }
 miette                             = { features = ["fancy"], version = "7.5" }
 tonic-prost-build                  = { workspace = true }
+
+[package.metadata.cargo-machete]
+ignored = [
+  "http",
+  "prost",
+  "tonic-prost", # used in generated OUT_DIR code
+]

bin/remote-prover/build.rs

@@ -1,28 +1,28 @@
+use std::path::{Path, PathBuf};
+
+use fs_err as fs;
 use miden_node_proto_build::remote_prover_api_descriptor;
-use miette::IntoDiagnostic;
+use miette::{IntoDiagnostic, WrapErr};
 use tonic_prost_build::FileDescriptorSet;
 
-/// Defines whether the build script should generate files in `/src`.
-///
-/// The docs.rs build pipeline has a read-only filesystem, so we have to avoid writing to `src`,
-/// otherwise the docs will fail to build there. Note that writing to `OUT_DIR` is fine.
-const BUILD_GENERATED_FILES_IN_SRC: bool = option_env!("BUILD_PROTO").is_some();
-
-const GENERATED_OUT_DIR: &str = "src/generated";
-
 /// Generates Rust protobuf bindings.
 fn main() -> miette::Result<()> {
     miden_node_rocksdb_cxx_linkage_fix::configure();
-    println!("cargo:rerun-if-env-changed=BUILD_PROTO");
-    if !BUILD_GENERATED_FILES_IN_SRC {
-        return Ok(());
-    }
+
+    let dst_dir =
+        PathBuf::from(std::env::var("OUT_DIR").expect("OUT_DIR should be set")).join("generated");
+
+    // Remove all existing files.
+    let _ = fs::remove_dir_all(&dst_dir);
+    fs::create_dir(&dst_dir)
+        .into_diagnostic()
+        .wrap_err("creating destination folder")?;
 
     // Get the file descriptor set
     let remote_prover_descriptor = remote_prover_api_descriptor();
 
     // Build tonic code
-    build_tonic_from_descriptor(remote_prover_descriptor)?;
+    build_tonic_from_descriptor(remote_prover_descriptor, &dst_dir)?;
 
     Ok(())
 }
@@ -31,9 +31,12 @@ fn main() -> miette::Result<()> {
 // ================================================================================================
 
 /// Builds tonic code from a `FileDescriptorSet`
-fn build_tonic_from_descriptor(descriptor: FileDescriptorSet) -> miette::Result<()> {
+fn build_tonic_from_descriptor(
+    descriptor: FileDescriptorSet,
+    dst_dir: &Path,
+) -> miette::Result<()> {
     tonic_prost_build::configure()
-        .out_dir(GENERATED_OUT_DIR)
+        .out_dir(dst_dir)
         .build_server(true)
         .build_transport(true)
         .compile_fds_with_config(descriptor, tonic_prost_build::Config::new())

bin/remote-prover/src/generated/mod.rs

@@ -2,5 +2,7 @@
 #![allow(clippy::allow_attributes, reason = "generated by build.rs and tonic")]
 
 #[rustfmt::skip]
-mod remote_prover;
+pub mod remote_prover {
+    include!(concat!(env!("OUT_DIR"), "/generated/remote_prover.rs"));
+}
 pub use remote_prover::*;