cargo-workflows

Cargo Workflows

Manage Rust projects with Cargo workspaces, feature flags, build scripts, and development tooling for productive, well-structured Rust development.

When to Use

• Organizing a multi-crate Rust project
• Adding optional functionality with feature flags
• Running code generation or native compilation with build.rs
• Preparing a crate for crates.io publication
• Setting up CI-friendly lint and format checks

Core Patterns

Pattern 1: Cargo Workspaces

Organize related crates in a single repository with shared dependencies and a unified build.

# Root Cargo.toml
[workspace]
resolver = "2"
members = [
    "crates/core",
    "crates/api",
    "crates/cli",
]

# Share dependency versions across workspace members
[workspace.dependencies]
serde = { version = "1", features = ["derive"] }
tokio = { version = "1", features = ["full"] }
anyhow = "1"
tracing = "0.1"

# Shared package metadata
[workspace.package]
edition = "2021"
rust-version = "1.75"
license = "MIT"
repository = "https://github.com/user/project"

# crates/core/Cargo.toml
[package]
name = "myproject-core"
version = "0.1.0"
edition.workspace = true
license.workspace = true

[dependencies]
serde.workspace = true        # uses workspace version
anyhow.workspace = true

project/
  Cargo.toml                  # workspace root
  Cargo.lock                  # single lock file for reproducibility
  crates/
    core/
      Cargo.toml
      src/lib.rs
    api/
      Cargo.toml
      src/lib.rs
    cli/
      Cargo.toml
      src/main.rs

Pattern 2: Feature Flags

Enable optional functionality without forcing dependencies on all users.

# Cargo.toml
[features]
default = ["json"]                   # enabled unless user opts out
json = ["dep:serde_json"]            # optional dependency
postgres = ["dep:sqlx", "sqlx/postgres"]
full = ["json", "postgres"]          # convenience feature combining others

[dependencies]
serde = { version = "1", features = ["derive"] }
serde_json = { version = "1", optional = true }
sqlx = { version = "0.7", optional = true, features = ["runtime-tokio"] }