astrid-runtime/astrid · error

Cargo include optional must be a boolean in {}

Error message

Cargo include optional must be a boolean in {}

What it means

Schema validation in cargo_config_includes: an include given as an inline table has an `optional` key whose value is not a boolean (e.g. a string "true" or an integer). TOML requires optional to be a real bool for the include semantics to be well-defined; load_content aborts and names the config file so the type error can be fixed.

Source

Thrown at crates/astrid-build/src/rust/config.rs:239

        return array
            .iter()
            .map(|value| {
                if let Some(include) = value.as_str() {
                    Ok(resolve_cargo_config_include(path, include, false)?)
                } else if let Some(table) = value.as_inline_table() {
                    let include = table
                        .get("path")
                        .and_then(toml_edit::Value::as_str)
                        .ok_or_else(|| {
                            anyhow::anyhow!(
                                "Cargo include table must contain a string path in {}",
                                path.display()
                            )
                        })?;
                    let optional = match table.get("optional") {
                        None => false,
                        Some(value) => value.as_bool().ok_or_else(|| {
                            anyhow::anyhow!(
                                "Cargo include optional must be a boolean in {}",
                                path.display()
                            )
                        })?,
                    };
                    Ok(resolve_cargo_config_include(path, include, optional)?)
                } else {
                    bail!(
                        "Cargo include array contains a non-string or non-table value in {}",
                        path.display()
                    )
                }
            })
            .collect();
    }
    if let Some(table) = item.as_table_like() {
        let include = table
            .get("path")

View on GitHub (pinned to affd8760f4)

Solutions

1. Change `optional` to an unquoted boolean: `optional = true`
2. Remove the `optional` key entirely to use the default (false)

Example fix

# before
include = { path = "x.toml", optional = "true" }
# after
include = { path = "x.toml", optional = true }

fn validate_optional_flag(t: &toml::Value) -> Result<(), String> {
    match t.get("optional") {
        None | Some(toml::Value::Boolean(_)) => Ok(()),
        Some(_) => Err("`optional` must be a boolean".into()),
    }
}

fn optional_is_bool(t: &toml::Value) -> bool {
    matches!(t.get("optional"), None | Some(toml::Value::Boolean(_)))
}

match load_content(...) {
    Err(e) if e.to_string().contains("optional must be a boolean") => {
        eprintln!("use unquoted true/false for `optional`");
    }
    other => other?,
}

When it happens

Trigger: load_content parsing `.cargo/config.toml` with an inline table like `include = { path = "x.toml", optional = "true" }` (string instead of boolean) at the inline-table branch.

Common situations: Quoting booleans by habit from other config formats (JSON/YAML strings); mistyping `optional = 1`.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• existing [security.capsule_local_egress].{capsule_id} is not
• Cargo include table must contain a string path in {}
• Cargo rustflags array contains a non-string value in {}
• No Cargo build target selected. Set `[build] target = "wasm3
• Capsule.toml has no package.name

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/1672acfefb4b6438. Report an issue: GitHub.