cargo-rustc — Compile the current package, and pass extra options to the compiler
cargo rustc [options] [
The specified target for the current package (or package specified by
provided) will be compiled along with all of its dependencies. The specified
args will all be passed to the final compiler invocation, not any of the
dependencies. Note that the compiler will still unconditionally receive
arguments such as
--crate-type, and the specified
args will simply be added to the compiler invocation.
See https://doc.rust-lang.org/rustc/index.html for documentation on rustc flags.
This command requires that only one target is being compiled when additional
arguments are provided. If more than one target is available for the current
package the filters of
--bin, etc, must be used to select which
target is compiled.
To pass flags to all compiler processes spawned by Cargo, use the
environment variable or the
build.rustflags config value.
By default, the package in the current working directory is selected. The
flag can be used to choose a different package in a workspace.
- The package to build. See cargo-pkgid(1) for the SPEC format.
When no target selection options are given,
cargo rustc will build all
binary and library targets of the selected package.
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.
is set when the integration test is built so that it can use the
env macro to locate the
Passing target selection flags will build only the specified targets.
--bench flags also
support common Unix glob patterns like
. 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.
- Build the package’s library.
- Build the specified binary. This flag may be specified multiple times and supports common Unix glob patterns.
- Build all binary targets.
- Build the specified example. This flag may be specified multiple times and supports common Unix glob patterns.
- Build all example targets.
- Build the specified integration test. This flag may be specified multiple times and supports common Unix glob patterns.
- Build all targets in test mode that have the
test = truemanifest 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
testflag in the manifest settings for the target.
- Build the specified benchmark. This flag may be specified multiple times and supports common Unix glob patterns.
- Build all targets in benchmark mode that have the
bench = truemanifest 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
benchflag in the manifest settings for the target.
- Build all targets. This is equivalent to specifying
--lib --bins --tests --benches --examples.
The feature flags allow you to control which features are enabled. When no
feature options are given, the
default feature is activated for every
See the features documentation for more details.
- Space or comma separated list of features to activate. Features of workspace
members may be enabled with
package-name/feature-namesyntax. This flag may be specified multiple times, which enables all specified features.
- Activate all available features of all selected packages.
- Do not activate the
defaultfeature of the selected packages.
- Build for the given architecture. The default is the host architecture. The general format of the triple is
rustc --print target-listfor a list of supported targets. This flag may be specified multiple times.
This may also be specified with the
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.
- Build optimized artifacts with the
releaseprofile. See also the
--profileoption for choosing a specific profile by name.
- Build with the given profile.
rustcsubcommand will treat the following named profiles with special behaviors:
check— Builds in the same way as the cargo-check(1) command with the
test— Builds in the same way as the cargo-test(1) command, enabling building in test mode which will enable tests and enable the
testcfg option. See rustc tests for more detail.
bench— Builds in the same was as the cargo-bench(1) command, similar to the
See the the reference for more details on profiles.
- Build the target even if the selected Rust compiler is older than the
required Rust version as configured in the project’s
- Output information how long each compilation takes, and track concurrency
information over time. Accepts an optional comma-separated list of output
--timingswithout an argument will default to
--timings=html. Specifying an output format (rather than the default) is unstable and requires
-Zunstable-options. Valid output formats:
-Zunstable-options): Write a human-readable file
target/cargo-timingsdirectory 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.
-Zunstable-options): Emit machine-readable JSON information about timing information.
- Build for the given crate type. This flag accepts a comma-separated list of
1 or more crate types, of which the allowed values are the same as
crate-typefield in the manifest for configuring a Cargo target. See
crate-typefield for possible values.
If the manifest contains a list, and
--crate-typeis provided, the command-line argument value will override what is in the manifest.
This flag only works when building a
- Directory for all generated artifacts and intermediate files. May also be
specified with the
CARGO_TARGET_DIRenvironment variable, or the
build.target-dirconfig value. Defaults to
targetin the root of the workspace.
- 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
- Do not print cargo log messages.
May also be specified with the
- 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
- 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: Emit shorter, human-readable text messages. Conflicts with
json: Emit JSON messages to stdout. See the reference for more details. Conflicts with
json-diagnostic-short: Ensure the
renderedfield of JSON messages contains the “short” rendering from rustc. Cannot be used with
json-diagnostic-rendered-ansi: Ensure the
renderedfield of JSON messages contains embedded ANSI color codes for respecting rustc’s default color scheme. Cannot be used with
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
- Path to the
Cargo.tomlfile. By default, Cargo searches for the
Cargo.tomlfile in the current directory or any parent directory.
- Either of these flags requires that the
Cargo.lockfile is up-to-date. If the lock file is missing, or it needs to be updated, Cargo will exit with an error. The
--frozenflag also prevents Cargo from attempting to access the network to determine if it is out-of-date.
These may be used in environments where you want to assert that the
Cargo.lockfile is up-to-date (such as a CI build) or want to avoid network access.
- 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
- If Cargo has been installed with rustup, and the first argument to
+, it will be interpreted as a rustup toolchain name (such as
+nightly). See the rustup documentation for more information about how toolchain overrides work.
--configKEY=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.
- 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-optionsflag to enable (see #10098).
- Prints help information.
- Unstable (nightly-only) flags to Cargo. Run
cargo -Z helpfor details.
- Number of parallel jobs to run. May also be specified with the
build.jobsconfig 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. Should not be 0.
- Build as many crates in the dependency graph as possible, rather than aborting
the build on the first one that fails to build. Unstable, requires
- Displays a future-incompat report for any future-incompatible warnings
produced during execution of this command
See the reference for details on environment variables that Cargo reads.
0: Cargo succeeded.
101: Cargo failed to complete.
Check if your package (not including dependencies) uses unsafe code:
cargo rustc --lib -- -D unsafe-code
Try an experimental flag on the nightly compiler, such as this which prints the size of every type:
cargo rustc --lib -- -Z print-type-sizes
crate-typefield in Cargo.toml with command-line option:
cargo rustc --lib --crate-type lib,cdylib