CARGO-BUILD(1)

📦 version 1.78.0, in ubuntu jammy, ubuntu noble

✨ NAME ✨

okay so bestie, welcome to cargo-build(1) from the General Commands Manual — and it's literally all about compiling the current package. no cap. 💖

🦋 SYNOPSIS 🦋

cargo build [options]

🌸 DESCRIPTION 🌸

Compile local packages and all of their dependencies. That's the whole vibe. 💅

✨ 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.

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.

  • -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.
  • --workspace — Build all members in the workspace.
  • --all — Deprecated alias for --workspace.
  • --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.

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.

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.

  • --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.

💖 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.

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.

💅 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.

okay real talk about that one up there — it's unstable, bestie, which means it only shows up on the nightly channel (https://doc.rust-lang.org/book/appendix-07-nightly-rust.html), and you have to unlock it with the -Z unstable-options flag. The full tea lives at https://github.com/rust-lang/cargo/issues/5579 if you wanna read more. 🫶

🎀 Manifest Options 🎀

  • --manifest-path path — hands Cargo the exact location of your Cargo.toml. Without it, Cargo goes looking for Cargo.toml in the current directory or any parent directory. 💅
  • --frozen, --locked — either one of these makes Cargo demand that Cargo.lock is already up-to-date. If the lock file is missing, or it needs to be updated, Cargo exits with an error, no negotiation. On top of that, --frozen also stops Cargo from reaching out to the network to figure out whether things are out-of-date. ✨

These are the flags you want in places where you need to assert that Cargo.lock is current (hi, CI builds 👋) or where you just can't have network access at all.

  • --offline — Cargo doesn't touch the network, for any reason, periodt. Without this flag, if Cargo needs the network and the network isn't there, it stops with an error. With this flag, Cargo will try to keep going without the network if it possibly can.
⚠️ careful though, because this can give you a different dependency resolution than online mode. Cargo locks itself to crates that are already downloaded locally, even if the local copy of the index says a newer version exists. Peep the cargo-fetch(1) command to download your dependencies before you go offline. 🙈

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

🌈 Common Options 🌈

  • +toolchain — if Cargo got installed via rustup, and the first argument to cargo starts with +, it gets read as a rustup toolchain name (think +stable or +nightly). The rustup documentation at https://rust-lang.github.io/rustup/overrides.html has the whole story on how toolchain overrides work. 👑
  • --config KEY=VALUE or PATH — overrides a Cargo configuration value. The argument should be TOML syntax of KEY=VALUE, or you can hand it a path to an extra configuration file. This flag can be specified multiple times (stack 'em up 🧚). See the command-line overrides section at https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides for more.
  • -C PATH — changes the current working directory before running any of the operations you asked for. That affects stuff like where Cargo looks by default for the project manifest (Cargo.toml), plus the directories it searches when discovering .cargo/config.toml, for example. This one has to come before the command name, like this:
cargo -C path/to/my-project build
💀 heads up: this option is only available on the nightly channel (https://doc.rust-lang.org/book/appendix-07-nightly-rust.html) and needs the -Z unstable-options flag enabled (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. Run cargo -Z help for the details.

🦋 Miscellaneous Options 🦋

  • -j N, --jobs N — how many parallel jobs to run. May also be specified 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 maximum number of parallel jobs to the number of logical CPUs plus the value you provided. If a string default is provided, it sets the value back to defaults. Should not be 0. 🚫
  • --keep-going — builds as many crates in the dependency graph as it can, instead of aborting the whole build the second one of them fails. 🫶

For example: if the current package depends on the dependencies fails and works, and one of them fails to build, cargo build -j1 may or may not build the one that succeeds (it all depends on which of the two Cargo picked to run first), whereas cargo build -j1 --keep-going would definitely run both builds, even if the one it ran first fails.

  • --future-incompat-report — displays a future-incompat report for any future-incompatible warnings produced while this command runs. 📋

See cargo-report(1).

🌟 ENVIRONMENT 🌟

See the reference at https://doc.rust-lang.org/cargo/reference/environment-variables.html for the details on the environment variables that Cargo reads. 👀

✨ 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)

and that's a wrap, bestie 💅 the lil footer stamp on this one is CARGO-BUILD(1) — that's the source/version and date tag, iykyk. go build something iconic ✨🦋🌈

📦 where this page comes from