cargo-rustc.txt

CARGO-RUSTC(1)

NAME
       cargo-rustc — Compile the current package, and pass extra options to
       the compiler

SYNOPSIS
       cargo rustc [options] [-- args]

DESCRIPTION
       The specified target for the current package (or package specified by -p
       if 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 -L, --extern, and
       --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 --lib, --bin, etc, must be used
       to select which target is compiled.

       To pass flags to all compiler processes spawned by Cargo, use the
       RUSTFLAGS environment variable
       <https://doc.rust-lang.org/cargo/reference/environment-variables.html>
       or the build.rustflags config value
       <https://doc.rust-lang.org/cargo/reference/config.html>.

OPTIONS
   Package Selection
       By default, the package in the current working directory is selected.
       The -p 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.

   Target Selection
       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. 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.

           The rustc subcommand will treat the following named profiles with
           special behaviors:

           o  check — Builds in the same way as the cargo-check(1) command
              with the dev profile.

           o  test — Builds in the same way as the cargo-test(1) command,
              enabling building in test mode which will enable tests and enable
              the test cfg option. See rustc tests
              <https://doc.rust-lang.org/rustc/tests/index.html> for more
              detail.

           o  bench — Builds in the same was as the cargo-bench(1) command,
              similar to the test profile.

           See the 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:

           o  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.

           o  json (unstable, requires -Zunstable-options): Emit
              machine-readable JSON information about timing information.

       --crate-type crate-type
           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-type field in the manifest for configuring a Cargo
           target. See crate-type field
           <https://doc.rust-lang.org/cargo/reference/cargo-targets.html#the-crate-type-field>
           for possible values.

           If the manifest contains a list, and --crate-type is provided, the
           command-line argument value will override what is in the manifest.

           This flag only works when building a lib or example library target.

   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.

   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:

           o  auto (default): Automatically detect if color support is
              available on the terminal.

           o  always: Always display colors.

           o  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:

           o  human (default): Display in a human-readable text format.
              Conflicts with short and json.

           o  short: Emit shorter, human-readable text messages. Conflicts with
              human and json.

           o  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.

           o  json-diagnostic-short: Ensure the rendered field of JSON messages
              contains the “short” rendering from rustc. Cannot be used
              with human or short.

           o  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.

           o  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.

   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.

       --frozen, --locked
           Either of these flags requires that the Cargo.lock file is
           up-to-date. If the lock file is missing, or it needs to be updated,
           Cargo will exit with an error. The --frozen flag 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.lock file is up-to-date (such as a CI build) or want to avoid
           network access.

       --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
           <https://doc.rust-lang.org/cargo/reference/config.html>.

   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
           <https://rust-lang.github.io/rustup/overrides.html> 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
           <https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides>
           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.

       -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
           <https://doc.rust-lang.org/cargo/reference/config.html>. 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.

       --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.
           Unstable, requires -Zunstable-options.

       --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
       <https://doc.rust-lang.org/cargo/reference/environment-variables.html>
       for details on environment variables that Cargo reads.

EXIT STATUS
       o  0: Cargo succeeded.

       o  101: Cargo failed to complete.

EXAMPLES
       1. Check if your package (not including dependencies) uses unsafe code:

              cargo rustc --lib -- -D unsafe-code

       2. 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

       3. Override crate-type field in Cargo.toml with command-line option:

              cargo rustc --lib --crate-type lib,cdylib

SEE ALSO
       cargo(1), cargo-build(1), rustc(1)