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 -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>.
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
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.
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.
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.
May also be specified with the term.color config value <https://doc.rust-lang.org/cargo/reference/config.html>.
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.
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>.
-j N, --jobs N
Profiles may be used to configure compiler options such as optimization levels and debug settings. See the reference <https://doc.rust-lang.org/cargo/reference/profiles.html> for more details.
Profile selection depends on the target and crate being built. By default the dev or test profiles are used. If the --release flag is given, then the release or bench profiles are used.
|Target||Default Profile||--release Profile|
|lib, bin, example||dev||release|
|test, bench, or any target in "test" or "bench" mode||test||bench|
Dependencies use the dev/release profiles.
See the reference <https://doc.rust-lang.org/cargo/reference/environment-variables.html> for details on environment variables that Cargo reads.
cargo rustc --lib -- -D unsafe-code
cargo rustc --lib -- -Z print-type-sizes