How to cross-compile a Rust project with Cargo

Cargo builds each Rust package for a target triple, and that triple controls the CPU, operating system, vendor, and ABI expected by the finished artifact. Cross-compiling matters when the build host is not the same environment that will run the binary or module.

Rustup supplies the target's Rust standard library, while Cargo's --target flag sends build output into a target-named directory. Using wasm32-wasip1 keeps the first cross build focused on Cargo and rustup because the target produces a .wasm artifact without requiring a separate target C linker.

Native targets can still need platform tools outside Rust, especially when crates link C code or when the target uses another system linker. Keep the target triple, linker or SDK, and final artifact path tied together so a successful build represents the environment you plan to deploy.

Steps to cross-compile a Rust project with Cargo:

Build or run the project for the host target first.

$ cargo run
   Compiling demo-cli v0.1.0 (/work/demo-cli)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.34s
     Running `target/debug/demo-cli`
Hello, world!

Run this from the directory that contains Cargo.toml. If the host build fails, fix that before adding a cross target.

Add the Rust standard library for the target.
```
$ rustup target add wasm32-wasip1
info: downloading component rust-std
```
Replace wasm32-wasip1 with another value from rustc --print target-list when your deployment target differs.
Build the package for the target triple.
```
$ cargo build --target wasm32-wasip1
   Compiling demo-cli v0.1.0 (/work/demo-cli)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.12s
```
Native targets such as x86_64-unknown-linux-musl, aarch64-unknown-linux-gnu, or mobile targets can need a target linker, C library, SDK, or Cargo target.<triple>.linker setting in addition to the Rust standard library.
Check the target-specific artifact path.
```
$ ls target/wasm32-wasip1/debug/demo-cli.wasm
target/wasm32-wasip1/debug/demo-cli.wasm
```
Debug artifacts stay under target/wasm32-wasip1/debug. Release artifacts from cargo build --release --target wasm32-wasip1 use target/wasm32-wasip1/release.