cargo-rustc - Compile the current package, and pass extra options to the compiler
cargo rustc [OPTIONS] [-- ARGS]
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.
- -p SPEC
- --package SPEC
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.
Passing target selection flags will build only the specified targets.
Build the package’s library.
- --bin NAME…
Build the specified binary. This flag may be specified multiple times.
Build all binary targets.
- --example NAME…
Build the specified example. This flag may be specified multiple times.
Build all example targets.
- --test NAME…
Build the specified integration test. This flag may be specified multiple times.
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.
- --bench NAME…
Build the specified benchmark. This flag may be specified multiple times.
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 the enabled features for the "current"
package. The "current" package is the package in the current directory, or the
one specified in
--manifest-path. If running in the root of a virtual
workspace, then the default features are selected for all workspace members,
or all features if
--all-features is specified.
When no feature options are given, the
default feature is activated for
every selected package.
- --features FEATURES
Space or comma separated list of features to activate. These features only apply to the current directory’s package. Features of direct dependencies may be enabled with
<dep-name>/<feature-name>syntax. 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 current directory’s package.
- --target TRIPLE
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 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 the PROFILES section for details on how this affects profile selection.
- --target-dir DIRECTORY
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
No output printed to stdout.
- --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
- --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.
short: Emit shorter, human-readable text messages.
json: Emit JSON messages to stdout. See the reference for more details.
json-diagnostic-short: Ensure the
renderedfield of JSON messages contains the "short" rendering from rustc.
json-diagnostic-rendered-ansi: Ensure the
renderedfield of JSON messages contains embedded ANSI color codes for respecting rustc’s default color scheme.
json-render-diagnostics: Instruct Cargo to not include rustc diagnostics in 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.
- --manifest-path PATH
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
Prints help information.
- -Z FLAG…
Unstable (nightly-only) flags to Cargo. Run
cargo -Z helpfor details.
- -j N
- --jobs N
Number of parallel jobs to run. May also be specified with the
build.jobsconfig value. Defaults to the number of CPUs.
Profiles may be used to configure compiler options such as optimization levels and debug settings. See the reference for more details.
Profile selection depends on the target and crate being built. By default the
test profiles are used. If the
--release flag is given, then the
bench profiles are used.
lib, bin, example
test, bench, or any target
Dependencies use the
See the reference for details on environment variables that Cargo reads.
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