cargo-rustc

Compile with extra rustc flags

$ cargo rustc -- [rustc_flags]

$ cargo rustc --bin [name] -- [flags]

$ cargo rustc --lib -- [-C opt-level=3]

$ cargo rustc -- -C [target-cpu=native]

$ cargo rustc -- -C [link-arg=-fuse-ld=lld]

cargo rustc [options] [-- args]

cargo rustc compiles the current package and passes extra options directly to the Rust compiler. Unlike `RUSTFLAGS`, which applies flags to all crates in the build, arguments after `--` are passed only to the final compiler invocation for the specified target, not to its dependencies.
This command is useful for enabling specific codegen options, changing optimization levels, emitting intermediate representations like LLVM IR or assembly, or passing custom linker arguments for a single crate without affecting the rest of the dependency graph.

--lib

Compile library only

Compile specified binary

Compile all binaries

Compile specified example

Compile specified test

Compile specified benchmark

Use release profile

Use specified profile

Package to compile

Target platform

Parallel jobs

Enable features

Enable all features

Common rustc flags:
- -C opt-level=N: Optimization level
- -C target-cpu=NAME: Target CPU
- -C link-arg=ARG: Linker argument
- --emit=TYPE: Output type (asm, llvm-ir, obj)

RUSTFLAGS

Pass flags to all rustc invocations

Only one target can be compiled when passing extra arguments. Use filters (--lib, --bin) to select target.

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