Identifying host os in cross-compiling

[notdanilo]

I am cross-compiling to wasm32-unknown-unknown and I would like to create a test for our CI. The problem is I can't find a standard way to identify the host_os and I tried to pass a --cfg to cargo test but it also doesn't seem possible.

I would be glad if someone point me to a documentation or maybe a workaround.

Here is the code I am trying to implement:

#[cfg(test)]
mod test {
    use super::Platform;

    use wasm_bindgen_test::wasm_bindgen_test;
    use wasm_bindgen_test::wasm_bindgen_test_configure;

    wasm_bindgen_test_configure!(run_in_browser);

    fn host_platform() -> Platform {
        #[cfg(host_os = "linux")]
        Platform::Linux
    }

    #[wasm_bindgen_test]
    fn platform() {
        assert_eq!(Platform::query(), host_platform())
    }
}

[Michael-F-Bryan]

You might need to write a build script and automatically optionally enable a run-in-browser feature, because that's guaranteed to be compiled+run on the host.

Cargo passes several useful environment variables to build scripts so they can know what the target and host platforms are.

[ratmice]

Just in addition to the environment variables here, using plain old cfg! in build.rs should refer to the hosts cfg as well.