Development with Cargo

Cargo provides the fastest iteration cycle for Rust development. While Bazel is NativeLink’s primary build system, Cargo offers a more traditional Rust development experience with excellent IDE integration.

Why Use Cargo?

Cargo is ideal when you need:

Fast Iteration - Quick compile-test cycles
IDE Support - Native rust-analyzer integration
Standard Workflow - Familiar Rust development patterns
Direct Dependencies - Transparent dependency management
Debugging - Better debugger integration

For production builds and CI, use Bazel to ensure reproducibility.

Setup

Prerequisites

Install Rust

Install Rust using rustup:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Verify you have the required version:

rustc --version
# Must be >= 1.87.0 (see Cargo.toml:12)

Install System Dependencies

Ubuntu/Debian
Arch Linux
macOS
Windows

sudo apt install pkg-config libssl-dev build-essential

sudo pacman -S pkg-config openssl base-devel

brew install openssl pkg-config

Install Development Tools

# rust-analyzer for IDE support
rustup component add rust-analyzer

# rustfmt for code formatting
rustup component add rustfmt

# clippy for linting
rustup component add clippy

Building

Basic Build Commands

Build Main Binary

# Debug build (fast compile, slower runtime)
cargo build

# Release build (slow compile, fast runtime)
cargo build --release

# Run the binary
./target/release/nativelink --help

Build All Workspace Crates

cargo build --workspace

# Or use --all (alias)
cargo build --all

Build Specific Crate

cargo build -p nativelink-config
cargo build -p nativelink-store
cargo build -p nativelink-worker

Build with Features

# Enable Nix features
cargo build --features nix

# Build worker with Nix support
cargo build -p nativelink-worker --features nix

Build Profiles

NativeLink defines custom build profiles in Cargo.toml:

# Default dev build
cargo build

# Fast compile, includes debug symbols
# Output: target/debug/nativelink

Testing

Running Tests

Run All Tests

# Run all tests in workspace
cargo test --all

# Run with output
cargo test --all -- --nocapture

Run Specific Crate Tests

cargo test -p nativelink-store
cargo test -p nativelink-scheduler
cargo test -p nativelink-worker

Run Specific Test

# Run test by name
cargo test test_function_name

# Run tests matching pattern
cargo test cache --all

Run Doc Tests

cargo test --doc --all

Test Configuration

# Run tests with multiple threads
cargo test --all -- --test-threads=4

# Run tests sequentially
cargo test --all -- --test-threads=1

# Show test output
cargo test --all -- --nocapture

# Run ignored tests
cargo test --all -- --ignored

# Run all tests including ignored
cargo test --all -- --include-ignored

Code Quality

Formatting

Check Formatting

cargo fmt --all -- --check

Fix Formatting

cargo fmt --all

Linting with Clippy

Run Clippy

# Run clippy on all crates
cargo clippy --all

# Run clippy with warnings as errors
cargo clippy --all -- -D warnings

Run Clippy on Tests

cargo clippy --all --tests

Fix Clippy Warnings

# Some issues can be auto-fixed
cargo clippy --all --fix

Lint Configuration

NativeLink enforces strict lints defined in Cargo.toml:96-213:

# Denied Rust lints (excerpt)
[workspace.lints.rust]
future-incompatible = "deny"
unsafe-op-in-unsafe-fn = "deny"
unused-imports = "deny"

# Clippy lints (excerpt)
[workspace.lints.clippy]
all = { level = "warn", priority = -1 }
nursery = { level = "warn", priority = -1 }
pedantic = { level = "warn", priority = -1 }
todo = "deny"
await-holding-lock = "deny"

See Cargo.toml for the complete list.

Documentation

Building Documentation

Build All Docs

# Build documentation for workspace
cargo doc --workspace --no-deps

# Open in browser
cargo doc --workspace --no-deps --open

Build Specific Crate Docs

cargo doc -p nativelink-config --open
cargo doc -p nativelink-store --open

Include Private Items

cargo doc --workspace --no-deps --document-private-items

Documentation Tests

# Run doc tests only
cargo test --doc --all

# Run doc tests for specific crate
cargo test --doc -p nativelink-util

Running NativeLink

Run with Cargo

Download Example Config

curl -O https://raw.githubusercontent.com/TraceMachina/nativelink/main/nativelink-config/examples/basic_cas.json5

Run Development Build

cargo run -- basic_cas.json5

Run Release Build

cargo run --release -- basic_cas.json5

Run with Environment Variables

RUST_LOG=debug cargo run --release -- basic_cas.json5

Binary Locations

# Debug binary
./target/debug/nativelink

# Release binary
./target/release/nativelink

# Smol profile binary
./target/smol/nativelink

Workspace Structure

NativeLink uses a Cargo workspace defined in Cargo.toml:2-7:

[workspace]
exclude = [
  "nativelink-config/generate-stores-config",
  "tools/generate-bazel-rc",
]
resolver = "2"

Workspace Crates

nativelink-config

Configuration parsing and validation

nativelink-error

Error types and handling

nativelink-scheduler

Task scheduling and execution

nativelink-service

gRPC service implementations

nativelink-store

Storage backends and caching

nativelink-util

Shared utilities and helpers

nativelink-worker

Remote execution worker

nativelink-macro

Procedural macros

nativelink-proto

Protocol buffer definitions

nativelink-metric

Metrics and telemetry

IDE Integration

rust-analyzer

rust-analyzer works out of the box with Cargo workspaces:

VS Code Setup

Install the rust-analyzer extension.Optional .vscode/settings.json:

{
  "rust-analyzer.check.command": "clippy",
  "rust-analyzer.cargo.features": "all"
}

Generate rust-project.json (Alternative)

For better integration with Bazel builds:

bazel run @rules_rust//tools/rust_analyzer:gen_rust_project

Then configure:

{
  "rust-analyzer.linkedProjects": ["rust-project.json"]
}

Debugging

VS Code
Command Line

Create .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "lldb",
      "request": "launch",
      "name": "Debug NativeLink",
      "cargo": {
        "args": ["build", "--bin=nativelink"]
      },
      "args": ["basic_cas.json5"],
      "cwd": "${workspaceFolder}"
    }
  ]
}

Install CodeLLDB extension.

# With rust-lldb
rust-lldb ./target/debug/nativelink

# With gdb
gdb ./target/debug/nativelink

Advanced Usage

Dependency Management

Update Dependencies

# Update to latest compatible versions
cargo update

# Update specific dependency
cargo update tokio

Check Outdated Dependencies

# Install cargo-outdated
cargo install cargo-outdated

# Check for updates
cargo outdated

Audit Dependencies

# Install cargo-audit
cargo install cargo-audit

# Check for security vulnerabilities
cargo audit

Build Performance

Parallel Builds
Incremental Compilation
Build Cache

# Use all CPU cores (default)
cargo build --release

# Limit parallel jobs
cargo build --release -j 4

# Enabled by default for debug builds
# Disable if needed:
CARGO_INCREMENTAL=0 cargo build

# Use sccache for distributed caching
cargo install sccache
export RUSTC_WRAPPER=sccache

cargo build --release

Cross-Compilation

# Install target
rustup target add x86_64-unknown-linux-musl
rustup target add aarch64-unknown-linux-musl

# Build for target
cargo build --release --target x86_64-unknown-linux-musl

# Static linking (musl)
cargo build --release --target x86_64-unknown-linux-musl

Troubleshooting

Cargo fails with OpenSSL errors

Install OpenSSL development headers:

# Ubuntu/Debian
sudo apt install libssl-dev

# Arch Linux
sudo pacman -S openssl

# macOS
brew install openssl

Or use vendored OpenSSL (if available):

cargo build --features vendored-openssl

Linker errors on macOS

Ensure Xcode Command Line Tools are installed:

xcode-select --install

Out of disk space

Clean build artifacts:

cargo clean

# Or clean specific profile
rm -rf target/debug
rm -rf target/release

Slow incremental builds

Clear incremental compilation cache:

rm -rf target/debug/incremental
rm -rf target/release/incremental

Clippy or rustfmt version mismatch

Update Rust toolchain:

rustup update
rustup component add clippy rustfmt

Cargo Tools

cargo-watch

Auto-rebuild on file changes

cargo install cargo-watch
cargo watch -x build

cargo-bloat

Find what takes space in binaries

cargo install cargo-bloat
cargo bloat --release

cargo-tree

Show dependency tree (built-in)

cargo tree

cargo-expand

Expand macros

cargo install cargo-expand
cargo expand

Development

Community

​Why Use Cargo?

​Setup

​Prerequisites

​Building

​Basic Build Commands

​Build Profiles

​Testing

​Running Tests

​Test Configuration

​Code Quality

​Formatting

​Linting with Clippy

​Lint Configuration

​Documentation

​Building Documentation

​Documentation Tests

​Running NativeLink

​Run with Cargo

​Binary Locations

​Workspace Structure

​Workspace Crates

nativelink-config

nativelink-error

nativelink-scheduler

nativelink-service

nativelink-store

nativelink-util

nativelink-worker

nativelink-macro

nativelink-proto

nativelink-metric

​IDE Integration

​rust-analyzer

​Debugging

​Advanced Usage

​Dependency Management

​Build Performance

​Cross-Compilation

​Troubleshooting

​Cargo Tools

cargo-watch

cargo-bloat

cargo-tree

cargo-expand

​Next Steps

Development with Bazel

Development with Nix

Build docs developers (and LLMs) love

Why Use Cargo?

Setup

Prerequisites

Building

Basic Build Commands

Build Profiles

Testing

Running Tests

Test Configuration

Code Quality

Formatting

Linting with Clippy

Lint Configuration

Documentation

Building Documentation

Documentation Tests

Running NativeLink

Run with Cargo

Binary Locations

Workspace Structure

Workspace Crates

IDE Integration

rust-analyzer

Debugging

Advanced Usage

Dependency Management

Build Performance

Cross-Compilation

Troubleshooting

Cargo Tools

Next Steps