windmill-labs/windmill · critical

Failed to parse Cargo.toml.default

Error message

Failed to parse Cargo.toml.default

What it means

default_manifest loads the vendored manifest/Cargo.toml.default (embedded via include_str!) and parses it into a TOML table to build the base manifest for Rust script dependency resolution. The .expect panics if the embedded default file is not valid TOML — this indicates a broken build artifact/shipped crate rather than user input, since the file is compiled into the binary.

Source

Thrown at backend/parsers/windmill-parser-rust/src/lib.rs:183

            match dep.contains('=') {
                true => {
                    r.push_str(dep);
                    r.push('\n');
                }
                false => {
                    r.push_str(dep);
                    r.push_str("=\"*\"\n");
                }
            }
        }

        toml::from_str(&r)
    }
}

fn default_manifest() -> toml::value::Table {
    toml::from_str(include_str!("../manifest/Cargo.toml.default"))
        .expect("Failed to parse Cargo.toml.default")
}

/**
* Get a `Manifest` that can be made into a TOML table. The format and logic are the same as in
* the rust-script or cargo-eval projects.
*/
fn find_embedded_manifest(s: &str) -> Option<Manifest> {
    find_short_hand_manifest(s).or_else(|| find_code_block_manifest(s))
}

fn find_short_hand_manifest(s: &str) -> Option<Manifest> {
    let re: Regex = Regex::new(r"^(?i)\s*//\s*cargo-deps\s*:(.*?)(\r\n|\n)").unwrap();
    /*
    This is pretty simple: the only valid syntax for this is for the first, non-blank line to contain a single-line comment whose first token is `cargo-deps:`.  That's it.
    */
    if let Some(cap) = re.captures(s) {
        if let Some(m) = cap.get(1) {
            return Some(Manifest::DepList(m.as_str().to_string()));

View on GitHub (pinned to e474e8803c)

Solutions

1. Validate the file: run `cargo metadata`-style check or any TOML linter on backend/parsers/windmill-parser-rust/manifest/Cargo.toml.default and fix syntax errors.
2. Restore the file with `git checkout -- backend/parsers/windmill-parser-rust/manifest/Cargo.toml.default`.
3. Rebuild cleanly (cargo clean) if a stale build artifact is suspected.
4. In code, replace expect with a descriptive anyhow error if you want a non-panicking path.

Example fix

// before
toml::from_str(include_str!("../manifest/Cargo.toml.default"))
    .expect("Failed to parse Cargo.toml.default")
// after
toml::from_str(include_str!("../manifest/Cargo.toml.default"))
    .map_err(|e| anyhow!("Failed to parse Cargo.toml.default: {e}"))?

// Validate the embedded default manifest is well-formed TOML at build/startup time
let raw = include_str!("../manifest/Cargo.toml.default");
let _table: toml::value::Table = toml::from_str(raw)
    .expect("bundled Cargo.toml.default is not valid TOML; restore the file");

// The call panics via expect; isolate if a broken artifact must not take the process down:
let manifest = std::panic::catch_unwind(default_manifest)
    .map_err(|_| anyhow!("Failed to parse Cargo.toml.default; check the shipped manifest file"))?;

When it happens

Trigger: parse_rust_deps_into_manifest calling default_manifest() when the bundled ../manifest/Cargo.toml.default cannot be deserialized by toml::from_str (e.g. corrupted or hand-edited manifest shipped in the crate).

Common situations: A modified/corrupted Cargo.toml.default in a source checkout or vendored dependency; a bad merge that left the TOML syntactically invalid; building from a partial/corrupted source tree.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Could not parse embedded manifest: {}
• unreachable, language is not supported: {language:#?}
• itered cannot be empty
• YAML emit error: {}
• hex string did not decode to an u64: {s}

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/c4a51118d5d8cfef. Report an issue: GitHub.