cargo build - The Cargo Book

# cargo-build(1)

## NAME

cargo-build — Compile the current package

## SYNOPSIS

`cargo build` [options]

## DESCRIPTION

Compile local packages and all of their dependencies.

## 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 workspaces 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 is set when the integration test is built so that it can use the `env` macro 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 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 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 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.

  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 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 for more details on profiles.
`--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. Defaults to `target` in the root of the workspace.
`--artifact-dir` directory
  Copy final artifacts to this directory.

  This option is unstable and available only on the nightly channel 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.
`-q`
`--quiet`
  Do not print cargo log messages. May also be specified with the `term.quiet` config value.
`--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.

`--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 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.

  This option is unstable and available only on the nightly channel and requires the `-Z unstable-options` flag to enable. See https://github.com/rust-lang/cargo/issues/5579 for more information.

### Manifest Options

`--manifest-path` path
  Path to the `Cargo.toml` file. By default, Cargo searches for the `Cargo.toml` file in the current directory or any parent directory.
`--ignore-rust-version`
  Ignore `rust-version` specification in packages.
`--locked`
  Asserts that the exact same dependencies and versions are used as when the existing `Cargo.lock` file was originally generated. Cargo will exit with an error when either of the following scenarios arises:
  - The lock file is missing.
  - Cargo attempted to change the lock file due to a different dependency resolution.

  It may be used in environments where deterministic builds are desired, such as in CI pipelines.

`--offline`
  Prevents Cargo from accessing the network for any reason. Without this flag, Cargo will stop with an error if it needs to access the network and the network is not available. With this flag, Cargo will attempt to proceed without the network if possible.

  Beware that this may result in different dependency resolution than online mode. Cargo will restrict itself to crates that are downloaded locally, even if there might be a newer version as indicated in the local copy of the index. See the cargo-fetch(1) command to download dependencies before going offline.

  May also be specified with the `net.offline` config value.

`--frozen`
  Equivalent to specifying both `--locked` and `--offline`.
`--lockfile-path` PATH
  Changes the path of the lockfile from the default (`<workspace_root>/Cargo.lock`) to PATH. PATH must end with `Cargo.lock` (e.g. `--lockfile-path /tmp/temporary-lockfile/Cargo.lock`). Note that providing `--lockfile-path` will ignore existing lockfile at the default path, and instead will either use the lockfile from PATH, or write a new lockfile into the provided PATH if it doesn’t exist. This flag can be used to run most commands in read-only directories, writing lockfile into the provided PATH.

  This option is only available on the nightly channel and requires the `-Z unstable-options` flag to enable (see #14421).

### Common Options

`+`toolchain
  If Cargo has been installed with rustup, and the first argument to `cargo` begins with `+`, it will be interpreted as a rustup toolchain name (such as `+stable` or `+nightly`). See the rustup documentation for more information about how toolchain overrides work.
`--config` KEY=VALUE or PATH
  Overrides a Cargo configuration value. The argument should be in TOML syntax of `KEY=VALUE`, or provided as a path to an extra configuration file. This flag may be specified multiple times. See the command-line overrides section for more information.
`-C` PATH
  Changes the current working directory before executing any specified operations. This affects things like where cargo looks by default for the project manifest (`Cargo.toml`), as well as the directories searched for discovering `.cargo/config.toml`, for example. This option must appear before the command name, for example `cargo -C path/to/my-project build`.

  This option is only available on the nightly channel and requires the `-Z unstable-options` flag to enable (see #10098).

`-h`
`--help`
  Prints help information.
`-Z` flag
  Unstable (nightly-only) flags to Cargo. Run `cargo -Z help` for details.

### Miscellaneous Options

`-j` N
`--jobs` N
  Number of parallel jobs to run. May also be specified with the `build.jobs` config value. Defaults to the number of logical CPUs. If negative, it sets the maximum number of parallel jobs to the number of logical CPUs plus provided value. If a string `default` is provided, it sets the value back to defaults. Should not be 0.
`--keep-going`
  Build as many crates in the dependency graph as possible, rather than aborting the build on the first one that fails to build.

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

`--future-incompat-report`
  Displays a future-incompat report for any future-incompatible warnings produced during execution of this command

  See cargo-report(1)

## ENVIRONMENT

See the reference for details on environment variables that Cargo reads.

## EXIT STATUS

- `0`: Cargo succeeded.
- `101`: Cargo failed to complete.

## EXAMPLES

1. Build the local package and all of its dependencies:

       cargo build

2. Build with optimizations:

       cargo build --release

## SEE ALSO

cargo(1), cargo-rustc(1)