clockworklabs/SpacetimeDB · error · anyhow::Error

wasm-bindgen detected. It seems like either you or a crate

Error message

wasm-bindgen detected.

It seems like either you or a crate in your dependency tree is depending on
wasm-bindgen. wasm-bindgen is only for webassembly modules that target the web
platform, and will not work in the context of SpacetimeDB.

To find the offending dependency, run `cargo tree -i wasm-bindgen`. Try checking
its cargo features for 'js' or 'web' or 'wasm-bindgen' to see if there's a way
to disable it.

What it means

Error "wasm-bindgen detected. It seems like either you or a crate in your dependency tree is depending on wasm-bindgen. wasm-bindgen is only for webassembly modules that target the web platform, and will not work in the context of SpacetimeDB. To find the offending dependency, run `cargo tree -i wasm-bindgen`. Try checking its cargo features for 'js' or 'web' or 'wasm-bindgen' to see if there's a way to disable it." thrown in clockworklabs/SpacetimeDB.

Source

Thrown at crates/cli/src/tasks/rust.rs:120

    }
    let artifact = artifact.context("no artifact found?")?;
    let artifact = artifact.filenames.into_iter().next().context("no wasm?")?;

    check_for_issues(artifact.as_ref())?;

    Ok(artifact.into())
}

fn check_for_issues(artifact: &Path) -> anyhow::Result<()> {
    // if this fails for some reason, just let it fail elsewhere
    let Ok(file) = fs::File::open(artifact) else {
        return Ok(());
    };
    let Ok(module) = wasmbin::Module::decode_from(&mut io::BufReader::new(file)) else {
        return Ok(());
    };
    if has_wasm_bindgen(&module) {
        anyhow::bail!(
            "wasm-bindgen detected.\n\
             \n\
             It seems like either you or a crate in your dependency tree is depending on\n\
             wasm-bindgen. wasm-bindgen is only for webassembly modules that target the web\n\
             platform, and will not work in the context of SpacetimeDB.\n\
             \n\
             To find the offending dependency, run `cargo tree -i wasm-bindgen`. Try checking\n\
             its cargo features for 'js' or 'web' or 'wasm-bindgen' to see if there's a way\n\
             to disable it."
        )
    }
    if has_getrandom(&module) {
        anyhow::bail!(
            "getrandom usage detected.\n\
             \n\
             It seems like either you or a crate in your dependency tree is depending on\n\
             the `getrandom` crate for random number generation. getrandom is the default\n\
             randomness source for the `rand` crate, and is used when you call\n\

View on GitHub (pinned to 524b4487d9)

When it happens

Trigger: Thrown at crates/cli/src/tasks/rust.rs:120 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of clockworklabs/SpacetimeDB@524b4487d9 (2026-08-16). Data as JSON: /api/errors/eec4500f25ff63f6. Report an issue: GitHub.