Cargo and Package Management

Cargo Commands

Cargo commands provide a unified command-line interface for creating, checking, building, testing, benchmarking, documenting, inspecting, and publishing Rust packages. In addition to built-in subcommands, any executable named cargo-<name> on your system PATH can be invoked directly as cargo <name>.

Daily Development Loop:
  cargo check  --->  cargo clippy  --->  cargo test  --->  cargo build --release
  (Type-check)       (Static lints)      (Run tests)       (Optimized binary)

Core Built-In Cargo Commands

Category Command Short Alias Description
Scaffolding cargo new <path> — Creates a new Cargo package in <path> (--lib for a library).
Scaffolding cargo init — Initializes a Cargo package in the current existing directory.
Compilation cargo check cargo c Type-checks code and dependencies without running LLVM codegen (much faster than build).
Compilation cargo build cargo b Compiles the package (--release for optimized production builds).
Execution cargo run cargo r Compiles and executes a binary target (--bin <name> or --example <name>).
Verification cargo test cargo t Compiles and runs unit, integration, and documentation tests.
Verification cargo bench — Compiles and runs benchmarks.
Quality cargo clippy — Runs the Clippy static analysis linter (--all-targets).
Quality cargo fmt — Formats all Rust source files with rustfmt (--check in CI).
Quality cargo fix — Automatically applies compiler-suggested machine-applicable lint and edition fixes.
Dependencies cargo add / cargo remove — Adds or removes dependencies in Cargo.toml.
Dependencies cargo tree — Prints a visual tree of the resolved dependency graph.
Dependencies cargo update — Updates versions recorded in Cargo.lock.
Maintenance cargo clean — Removes the target/ directory (or specific package artifacts with -p <pkg>).
Distribution cargo doc cargo d Generates HTML API documentation (--open).
Distribution cargo publish — Packages and uploads a crate to crates.io (--dry-run to test locally).
Distribution cargo install <crate> — Builds and installs a binary crate into ~/.cargo/bin/ (--locked).

Inspecting the Dependency Graph with cargo tree

cargo tree is built directly into Cargo and helps diagnose why a transitive crate is included, which features are enabled on each crate (-e features), or why two versions of the same crate exist in the graph (--duplicates):

# 1. Show why a specific transitive crate (`syn`) is pulled into the build
cargo tree --invert syn

# 2. List all duplicate crate versions in the dependency graph
cargo tree --duplicates

# 3. Show active feature flags across the dependency graph
cargo tree -e features

my_app v0.1.0 (/Users/dev/my_app)
└── serde v1.0.218
    └── serde_derive v1.0.218 (proc-macro)
        └── syn v2.0.98

How Custom Subcommands Work (cargo-<name>)

When you run cargo nextest or cargo audit, Cargo searches the directories in your PATH for an executable named cargo-nextest or cargo-audit and invokes it, passing nextest or audit as the first argument (argv[1]):

fn resolve_subcommand_binary(subcommand: &str) -> String {
    format!("cargo-{subcommand}{}", std::env::consts::EXE_SUFFIX)
}

fn main() {
    println!("Subcommand binary for 'audit': {}", resolve_subcommand_binary("audit"));
}

Subcommand binary for 'audit': cargo-audit