How can I set default build target for Cargo?

Question

I tried to make 'Hello World' in Rust using this tutorial, but the build command is a bit verbose:

cargo +nightly build --target wasm32-unknown-unknown --release

Is it possible to set the default target for cargo build?

score 77 · Accepted Answer · edited Feb 06 '23 at 08:37

77

You could use a Cargo configuration file to specify a default target-triple for your project. In your project's root, create a .cargo directory and a config.toml file in it with the following contents:

[build]
target = "wasm32-unknown-unknown"

edited Feb 06 '23 at 08:37

citelao

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answered Mar 23 '18 at 15:50

mexus

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Is it work expectedly too now? I got the warning: `warning: unused manifest key: build` using 1.47.0-nightly. – Usagi Ito Aug 20 '20 at 12:19
8

Are you putting it in `Cargo.toml`?. You need to use `.cargo/config` – Jeff Muizelaar Sep 15 '20 at 21:45
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Additional note: while you absolutely can call the file `config`, you can also call it `config.toml`. It will behave excactly the same, but your editor might now improve syntax highlighting and whatnot. – Zachary Perkins Aug 16 '22 at 03:54
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@ZacharyPerkins: From what I know the `config.toml` filename with extension included is not supported for older versions of Cargo (released before ~2020). For current versions it is the preferred name, though. – blerontin Apr 17 '23 at 10:29

score 21 · Answer 2 · answered Mar 23 '18 at 15:49

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As listed in the Cargo documentation, you can create a .cargo/config and specify the target:

[build]
target = "my-custom-target"

answered Mar 23 '18 at 15:49

Shepmaster

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Thank you! And for others reading this in the future, you can see what targets Rust supports using `rustc --print target-list`. – C. Dunn Nov 05 '20 at 13:22
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@C.Dunn And if using rustup, you can do `rustup target list` as well. – Peter Hansen Apr 11 '22 at 02:55

score 4 · Answer 3 · answered Oct 20 '22 at 11:17

If you're able to use unstable features, following documentation and especially per-package-target feature add this to you crate manifest that usually named Cargo.toml

cargo-features = ["per-package-target"]

[package]
forced-target = "wasm32-unknown-unknown"
# and/or:
default-target = "wasm32-unknown-unknown"

This requires nightly toolchain.

How can I set default build target for Cargo?

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