CARGO-BUILD(1)

📦 version 1.76.0, in ubuntu jammy, ubuntu noble

💖 cargo-build(1) — General Commands Manual, but bestie-coded 💖

✨ NAME ✨

cargo-build — compile the current package. That’s the whole assignment, bestie. 🛠️✨

✨ SYNOPSIS ✨

cargo build [options]

✨ DESCRIPTION ✨

Compile local packages and all of their dependencies. It’s giving “build button, but make it terminal.” 💅

✨ OPTIONS ✨

📦 Package Selection 📦

By default, when no package selection options are given, the packages selected depend on the selected manifest file (based on the current working directory if --manifest-path is not given). If the manifest is the root of a workspace then the workspace’s default members are selected, otherwise only the package defined by the manifest will be selected. No cap. 🫶

The default members of a workspace can be set explicitly with the workspace.default-members key in the root manifest. If this is not set, a virtual workspace will include all workspace members (equivalent to passing --workspace), and a non-virtual workspace will include only the root crate itself. Iconic behavior, honestly. 👑

  • -p *spec*…, --package *spec*… — Build only the specified packages. See cargo-pkgid(1) for the SPEC format. This flag may be specified multiple times and supports common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each pattern. Shell girlies, beware. 😭
  • --workspace — Build all members in the workspace.
  • --all — Deprecated alias for --workspace. She’s deprecated, but she’s still showing up to the group chat. 💀
  • --exclude *SPEC*… — Exclude the specified packages. Must be used in conjunction with the --workspace flag. This flag may be specified multiple times and supports common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each pattern.

🎯 Target Selection 🎯

When no target selection options are given, cargo build will build all binary and library targets of the selected packages. Binaries are skipped if they have required-features that are missing. So if your fave isn’t showing up, check those required features, bestie. 👀

Binary targets are automatically built if there is an integration test or benchmark being selected to build. This allows an integration test to execute the binary to exercise and test its behavior. The CARGO_BIN_EXE_<name> environment variable (https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-crates) is set when the integration test is built so that it can use the env macro (https://doc.rust-lang.org/std/macro.env.html) to locate the executable. Main character energy for your test suite. 🌟

Passing target selection flags will build only the specified targets.

Note that --bin, --example, --test and --bench flags also support common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each glob pattern. Protect your globs, protect your peace. 🫶

  • --lib — Build the package’s library.
  • --bin *name*… — Build the specified binary. This flag may be specified multiple times and supports common Unix glob patterns.
  • --bins — Build all binary targets.
  • --example *name*… — Build the specified example. This flag may be specified multiple times and supports common Unix glob patterns.
  • --examples — Build all example targets.
  • --test *name*… — Build the specified integration test. This flag may be specified multiple times and supports common Unix glob patterns.
  • --tests — Build all targets in test mode that have the test = true manifest flag set. By default this includes the library and binaries built as unittests, and integration tests. Be aware that this will also build any required dependencies, so the lib target may be built twice (once as a unittest, and once as a dependency for binaries, integration tests, etc.). Targets may be enabled or disabled by setting the test flag in the manifest settings for the target.
  • --bench *name*… — Build the specified benchmark. This flag may be specified multiple times and supports common Unix glob patterns.
  • --benches — Build all targets in benchmark mode that have the bench = true manifest flag set. By default this includes the library and binaries built as benchmarks, and bench targets. Be aware that this will also build any required dependencies, so the lib target may be built twice (once as a benchmark, and once as a dependency for binaries, benchmarks, etc.). Targets may be enabled or disabled by setting the bench flag in the manifest settings for the target.
  • --all-targets — Build all targets. This is equivalent to specifying --lib --bins --tests --benches --examples. The “do everything” button, periodt. 💅

🌸 Feature Selection 🌸

The feature flags allow you to control which features are enabled. When no feature options are given, the default feature is activated for every selected package. Defaults are doing their little default thing. ✨

See the features documentation (https://doc.rust-lang.org/cargo/reference/features.html#command-line-feature-options) for more details.

  • -F features, --features features — Space or comma separated list of features to activate. Features of workspace members may be enabled with package-name/feature-name syntax. This flag may be specified multiple times, which enables all specified features.
  • --all-features — Activate all available features of all selected packages.
  • --no-default-features — Do not activate the default feature of the selected packages.

⚙️ Compilation Options ⚙️

  • --target triple — Build for the given architecture. The default is the host architecture. The general format of the triple is <arch><sub>-<vendor>-<sys>-<abi>. Run rustc --print target-list for a list of supported targets. This flag may be specified multiple times.

This may also be specified with the build.target config value (https://doc.rust-lang.org/cargo/reference/config.html).

Note that specifying this flag makes Cargo run in a different mode where the target artifacts are placed in a separate directory. See the build cache (https://doc.rust-lang.org/cargo/guide/build-cache.html) documentation for more details.

  • -r, --release — Build optimized artifacts with the release profile. See also the --profile option for choosing a specific profile by name.
  • --profile name — Build with the given profile. See the reference (https://doc.rust-lang.org/cargo/reference/profiles.html) for more details on profiles.
  • --ignore-rust-version — Build the target even if the selected Rust compiler is older than the required Rust version as configured in the project’s rust-version field.
  • --timings=fmts — Output information how long each compilation takes, and track concurrency information over time. Accepts an optional comma-separated list of output formats; --timings without an argument will default to --timings=html. Specifying an output format (rather than the default) is unstable and requires -Zunstable-options. Valid output formats:
    • html (unstable, requires -Zunstable-options): Write a human-readable file cargo-timing.html to the target/cargo-timings directory with a report of the compilation. Also write a report to the same directory with a timestamp in the filename if you want to look at older runs. HTML output is suitable for human consumption only, and does not provide machine-readable timing data.
    • json (unstable, requires -Zunstable-options): Emit machine-readable JSON information about timing information.

📁 Output Options 📁

  • --target-dir directory — Directory for all generated artifacts and intermediate files. May also be specified with the CARGO_TARGET_DIR environment variable, or the build.target-dir config value (https://doc.rust-lang.org/cargo/reference/config.html). Defaults to target in the root of the workspace.
  • --out-dir directory — Copy final artifacts to this directory.
🚨 This option is unstable and available only on the nightly channel (https://doc.rust-lang.org/book/appendix-07-nightly-rust.html) and requires the -Z unstable-options flag to enable. See https://github.com/rust-lang/cargo/issues/6790 for more information. Nightly girlies only, bestie. 🌙

💬 Display Options 💬

  • -v, --verbose — Use verbose output. May be specified twice for “very verbose” output which includes extra output such as dependency warnings and build script output. May also be specified with the term.verbose config value (https://doc.rust-lang.org/cargo/reference/config.html).
  • -q, --quiet — Do not print cargo log messages. May also be specified with the term.quiet config value (https://doc.rust-lang.org/cargo/reference/config.html).
  • --color when — Control when colored output is used. Valid values:
    • auto (default): Automatically detect if color support is available on the terminal.
    • always: Always display colors.
    • never: Never display colors.

May also be specified with the term.color config value (https://doc.rust-lang.org/cargo/reference/config.html).

  • --message-format fmt — The output format for diagnostic messages. Can be specified multiple times and consists of comma-separated values. Valid values:
    • human (default): Display in a human-readable text format. Conflicts with short and json.
    • short: Emit shorter, human-readable text messages. Conflicts with human and json.
    • json: Emit JSON messages to stdout. See the reference (https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages) for more details. Conflicts with human and short.
    • json-diagnostic-short: Ensure the rendered field of JSON messages contains the “short” rendering from rustc. Cannot be used with human or short.
    • json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messages contains embedded ANSI color codes for respecting rustc’s default color scheme. Cannot be used with human or short.
    • json-render-diagnostics: Instruct Cargo to not include rustc diagnostics in JSON messages printed, but instead Cargo itself should render the JSON diagnostics coming from rustc. Cargo’s own JSON diagnostics and others coming from rustc are still emitted. Cannot be used with human or short.
  • --build-plan — Outputs a series of JSON messages to stdout that indicate the commands to run the build.
heads up bestie, this one is unstable — it's only available on the nightly channel and needs the -Z unstable-options flag to turn on. more deets over at <https://github.com/rust-lang/cargo/issues/5579> 💅

🌸 Manifest Options 🌸

  • --manifest-path path — points Cargo at your Cargo.toml file directly. no path given? then Cargo goes hunting for Cargo.toml in the current directory, and if it's not there, in every parent directory up the tree. it will find it fr fr 🔍
  • --frozen, --locked — either one of these makes Cargo demand that Cargo.lock is already up-to-date. missing lock file? needs updating? Cargo just exits with an error, no notes. 💀

--frozen is the extra-strict one: it also stops Cargo from touching the network to check whether things are out of date.

these are your go-to when you want to assert that Cargo.lock is current (CI builds, looking at you 👀) or when you want to dodge network access entirely.

  • --offline — Cargo is banned from the network for any reason whatsoever. normally, if Cargo needs the network and there isn't any, it just errors out. with this flag, it'll try its best to keep going without it. 🧚
⚠️ beware bestie: this can give you different dependency resolution than online mode. Cargo restricts itself to crates you've already downloaded locally, even if the local copy of the index says a newer version exists. want to prep for offline? go run cargo-fetch(1) first to download your deps. 💖

you can also set this with the net.offline config value — see <https://doc.rust-lang.org/cargo/reference/config.html>.

✨ Common Options ✨

  • +toolchain — if Cargo came in via rustup and the very first argument to cargo starts with +, Cargo reads it as a rustup toolchain name (think +stable or +nightly). the whole toolchain-override situation is explained in the rustup docs: <https://rust-lang.github.io/rustup/overrides.html> 🦋
  • --config KEY=VALUE or PATH — overrides a Cargo config value. the argument is either TOML syntax in KEY=VALUE form, or a path to an extra config file. you can pass this flag multiple times and it stacks. more over at the command-line overrides section: <https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides> 🎀
  • -C PATH — changes the current working directory before running any of the specified operations. so it affects where Cargo looks by default for the project manifest (Cargo.toml), and which directories get searched when discovering .cargo/config.toml, for example. it has to come before the command name, like this:
cargo -C path/to/my-project build
🙈 this one is nightly-only and requires the -Z unstable-options flag to enable (see #10098 at <https://github.com/rust-lang/cargo/issues/10098>).
  • -h, --help — prints help information. the classic. 🫶
  • -Z flag — the unstable (nightly-only) flags for Cargo live here. run cargo -Z help for the full list. 🔥

🎀 Miscellaneous Options 🎀

  • -j N, --jobs N — how many parallel jobs to run. can also be set with the build.jobs config value (<https://doc.rust-lang.org/cargo/reference/config.html>). defaults to the number of logical CPUs. if it's negative, it sets the max parallel jobs to the number of logical CPUs plus the value you gave. if you pass the string default, it resets back to the defaults. and it should not be 0. ⭐
  • --keep-going — keeps building as many crates in the dependency graph as it possibly can, instead of bailing on the first one that fails to build. the way that this changes things… iconic.

for example: say your current package depends on two dependencies, fails and works, and one of them fails to build. cargo build -j1 may or may not build the one that succeeds — it depends on which of the two Cargo happened to pick to run first. but cargo build -j1 --keep-going would definitely run both builds, even if the first one it ran fails. 💪

  • --future-incompat-report — displays a future-incompat report for any future-incompatible warnings that popped up while this command ran. see cargo-report(1) for more. 👑

🌈 ENVIRONMENT 🌈

all the environment variables Cargo reads? they're documented over in the reference: <https://doc.rust-lang.org/cargo/reference/environment-variables.html> 💜

💖 EXIT STATUS 💖

  • 0: Cargo succeeded. slay. ✨
  • 101: Cargo failed to complete. 😭

🌸 EXAMPLES 🌸

  1. Build the local package and all of its dependencies:
cargo build
  1. Build with optimizations:
cargo build --release

🦋 SEE ALSO 🦋

cargo(1), cargo-rustc(1)

okay bestie that's the whole page, you ate it 💅 this was CARGO-BUILD(1) from the Cargo source/version and date noted in the original footer — go build something iconic, periodt. 🎀✨

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