Rust 找不到“标准”的“板条箱”

Question

I'm trying to get a.wasm file via RUSTFLAGS='-C link-arg=-s' cargo build --release --target wasm32-unknown-unknown but get the error:

error[E0463]: can't find crate for `std`

When i type rustup target add wasm32-unknown-unknown i get:

info: component 'rust-std' for target 'wasm32-unknown-unknown' is up to date

I installed Rust and Rustup separate via chocolatey.

• rustc 1.58.0
• rustup 1.24.3
• info: The currently active rustc version is rustc 1.60.0-nightly (5e57faa78 2022-01-19)

Answer 1

You need to add the wasm32-unknown-unknown target for the nightly toolchain if that's what you are using:

rustup target add --toolchain nightly wasm32-unknown-unknown

Answer 2

I suffered the same symptoms after initialized a new cargo project on macOS but my problem was not adding to the wrong toolchain.

In my case, the problem was multiple cargo binaries. I discovered this after running which cargo and seeing it installed via homebrew. I did rustup self uninstall (perhaps unnecessary), homebrew uninstall rust and, then reinstalled rust according to the official docs and wasm32-unknown-unknown and then the cargo build --release --target wasm32-unknown-unknown command worked as expected.