GitHub Workflows

Diagnose, fix, and optimize GitHub Actions workflows for Rust projects.

Purpose

Set up robust CI/CD pipelines for Rust projects with proper caching, testing, linting, and release automation.

Quick Reference

• Caching Strategies - Manual cache, rust-cache, sccache, cache keys
• Troubleshooting - Common issues, debugging, fixes
• Advanced Features - Releases, coverage, security, docs deployment

Complete Rust CI Workflow (2025)

name: Rust CI

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]

env:
  CARGO_TERM_COLOR: always
  RUST_BACKTRACE: 1

jobs:
  check:
    name: Check
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable

      - name: Cache Rust dependencies
        uses: Swatinem/rust-cache@v2

      - name: Run cargo check
        run: cargo check --all --verbose

  fmt:
    name: Format
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable
        with:
          components: rustfmt

      - name: Check formatting
        run: cargo fmt -- --check

  clippy:
    name: Clippy
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy

      - name: Cache Rust dependencies
        uses: Swatinem/rust-cache@v2

      - name: Run clippy
        run: cargo clippy --all-targets --all-features -- -D warnings

  test:
    name: Test
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
        rust: [stable]
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: ${{ matrix.rust }}

      - name: Cache Rust dependencies
        uses: Swatinem/rust-cache@v2

      - name: Run tests
        run: cargo test --all --verbose

      - name: Run tests with all features
        run: cargo test --all-features --verbose

  coverage:
    name: Coverage
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable

      - name: Install cargo-llvm-cov
        run: cargo install cargo-llvm-cov

      - name: Generate coverage
        run: cargo llvm-cov --lcov --all-features --workspace --output-path lcov.info

      - name: Upload coverage to Codecov
        uses: codecov/codecov-action@v4
        with:
          file: ./lcov.info
          fail_ci_if_error: false

Quick Start Workflows

Minimal CI (Quick Feedback)

name: Quick CI

on: [push, pull_request]

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - run: cargo check --all
      - run: cargo fmt -- --check
      - run: cargo clippy -- -D warnings
      - run: cargo test --all

Project-Specific: Self-Learning Memory CI

name: Self-Learning Memory CI

on:
  push:
    branches: [main]
  pull_request:

env:
  CARGO_TERM_COLOR: always
  RUST_BACKTRACE: 1

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - run: cargo check --all --verbose

  fmt:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: rustfmt
      - run: cargo fmt -- --check

  clippy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy
      - uses: Swatinem/rust-cache@v2
      - run: cargo clippy --all-targets -- -D warnings

  test:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - run: cargo test --all --verbose
      - run: cargo test --all --all-features --verbose

Common Tasks

Setup Rust Toolchain

# Stable
- uses: dtolnay/rust-toolchain@stable

# With components
- uses: dtolnay/rust-toolchain@stable
  with:
    components: rustfmt, clippy

# Specific version
- uses: dtolnay/rust-toolchain@master
  with:
    toolchain: 1.75.0

Cache Dependencies

# Recommended: Use rust-cache (automatic)
- uses: Swatinem/rust-cache@v2
  with:
    shared-key: "stable"
    save-if: ${{ github.ref == 'refs/heads/main' }}

# Alternative: Manual cache
- uses: actions/cache@v4
  with:
    path: |
      ~/.cargo/registry/index
      ~/.cargo/registry/cache
      target
    key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
    restore-keys: |
      ${{ runner.os }}-cargo-
    save-always: true

See caching-strategies.md for detailed caching options.

Run Tests

# All tests
- run: cargo test --all

# With verbose output
- run: cargo test --all --verbose

# With all features
- run: cargo test --all-features

# With backtrace
- run: RUST_BACKTRACE=1 cargo test --all

# Single-threaded (for race conditions)
- run: cargo test --all -- --test-threads=1

Build Project

# Development build
- run: cargo build --all

# Release build
- run: cargo build --release --all

# With timing info
- run: cargo build --release --timings

Lint and Format

Using cargo-llvm-cov (Recommended)

- name: Install llvm-cov
  run: cargo install cargo-llvm-cov

- name: Generate coverage
  run: cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info

- name: Upload to Codecov
  uses: codecov/codecov-action@v4
  with:
    files: lcov.info
    token: ${{ secrets.CODECOV_TOKEN }}

Alternative: Generate multiple formats

- name: Install llvm-cov
  run: cargo install cargo-llvm-cov

- name: Generate coverage (HTML + LCOV)
  run: |
    cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info
    cargo llvm-cov --all-features --workspace --html --output-dir coverage

# Run clippy with fix
- run: cargo clippy --fix

Best Practices (2025)

DO:

✓ Use actions/cache@v4 with save-always: true ✓ Use hashFiles('**/Cargo.lock') for cache keys ✓ Implement restore-keys for cache fallback ✓ Use dtolnay/rust-toolchain (not deprecated actions-rs) ✓ Split large caches to avoid 2GB limit ✓ Test on multiple platforms (matrix) ✓ Use Swatinem/rust-cache@v2 for simplicity ✓ Cache both registry and target directory ✓ Set CARGO_TERM_COLOR: always for readable logs ✓ Use continue-on-error for experimental builds

DON'T:

✗ Use deprecated actions-rs/* actions ✗ Create monolithic cache entries >2GB ✗ Cache without restore-keys ✗ Forget save-always: true for partial builds ✗ Cache target/ across different jobs without unique keys ✗ Run expensive operations on every PR ✗ Use actions/cache@v3 and @v4 inconsistently ✗ Hardcode Rust version (use rust-toolchain file)

Common Issues

Quick reference - see troubleshooting.md for full details:

1. Cache not saved on failure → Use save-always: true
2. Cache key mismatch → Use hashFiles() and restore-keys
3. Deprecated actions-rs → Use dtolnay/rust-toolchain
4. tar creation errors → Use rust-cache or exclude problematic paths
5. Files >2GB → Split into smaller caches
6. Workflow permissions → Set permissions: in workflow
7. Flaky tests → Add retries with nick-fields/retry@v2

Detailed Documentation

• Caching Strategies - All caching methods, cache keys, performance tips
• Troubleshooting - Issues, fixes, debugging, monitoring
• Advanced Features - Releases, coverage, security, multi-platform

Integration with Project

For the rust-self-learning-memory project, the workflow ensures all memory-core, memory-storage-turso, and memory-storage-redb crates are properly tested across platforms with appropriate caching and security checks.

Quick Checklist

Before committing workflow changes:

• Uses actions/cache@v4 or Swatinem/rust-cache@v2
• Has save-always: true for caches
• Uses dtolnay/rust-toolchain (not actions-rs)
• Caches are <2GB each
• Has restore-keys for fallback
• Tests on multiple platforms (if needed)
• Clippy runs with -D warnings
• Format check included
• Permissions set appropriately