astrid-runtime/astrid · critical

failed to create wasmtime engine for hooks

Error message

failed to create wasmtime engine for hooks

What it means

`build_hook_engine` constructs the shared `wasmtime::Engine` for WASM hooks with the component model enabled, GC/exceptions disabled, and epoch interruption on. It panics if wasmtime cannot create the engine — an unrecoverable misconfiguration, since every hook handler depends on this engine.

Source

Thrown at crates/astrid-hooks/src/handler/wasm.rs:78

        http.default_timeout_secs,
        http.stream_connect_timeout_secs,
        http.stream_read_timeout_secs,
        http.header_deadline_secs,
        http.max_redirects,
        http.max_concurrent_streams,
        http.max_response_bytes,
    )
}

/// Build the hook engine with Astrid's explicit guest-feature boundary.
fn build_hook_engine() -> wasmtime::Engine {
    let mut wt_config = wasmtime::Config::new();
    wt_config
        .wasm_component_model(true)
        .wasm_gc(false)
        .wasm_exceptions(false)
        .epoch_interruption(true);
    wasmtime::Engine::new(&wt_config).expect("failed to create wasmtime engine for hooks")
}

/// Handler for WASM components.
///
/// Lazily compiles the WASM component on first invocation and caches the
/// compiled [`Component`] (immutable, thread-safe) for subsequent calls.
/// A fresh [`Store`] is created for each invocation.
pub(crate) struct WasmHandler {
    /// Cached wasmtime engine (shared across all components).
    engine: wasmtime::Engine,
    /// Cached compiled components (lazy-loaded, keyed by module path).
    cached_components: Mutex<HashMap<String, Arc<Component>>>,
    /// Configuration for WASM execution.
    config: WasmConfig,
    /// KV store for hook state (scoped to `hook:wasm`).
    kv: Option<ScopedKvStore>,
    /// Workspace root for file operations.
    workspace_root: PathBuf,

View on GitHub (pinned to affd8760f4)

Solutions

1. Enable the required wasmtime Cargo features (e.g. `component-model`) so `wasm_component_model(true)` is supported.
2. Check wasmtime release notes for config-option conflicts; remove options the new version rejects.
3. Downgrade/upgrade the wasmtime crate to a version compatible with this configuration.
4. Replace the expect with a `Result` return so host startup reports the underlying wasmtime error message.

Example fix

// before
wasmtime::Engine::new(&wt_config).expect("failed to create wasmtime engine for hooks")
// after
wasmtime::Engine::new(&wt_config)
    .map_err(|e| HookError::EngineInit(format!("wasmtime engine init failed: {e}")))?

// Rust (build check): ensure the component-model feature is enabled
cargo tree -e features | grep -q component-model || echo "wasmtime component-model feature missing"

// Rust: propagate engine init failure to callers
let engine = wasmtime::Engine::new(&wt_config)
    .map_err(|e| HookError::EngineInit(e.to_string()))?;

When it happens

Trigger: Calling `wasmtime::Engine::new(&wt_config)` with `wasm_component_model(true)` when the linked wasmtime build lacks component-model support (feature flags off), or when conflicting config options are set (e.g. GC disabled incompatibly with the component model on some wasmtime versions).

Common situations: Mismatches between Cargo feature flags and runtime config after a wasmtime version upgrade, a wasmtime build compiled without the `component-model` feature, or mutually exclusive config options introduced by a new wasmtime release.

Related errors

• build_host_state
• WASM capsule has no BLAKE3 hash in meta.json
• stability quantiles must lie strictly between zero and 10,00
• stability quantiles select duplicate boundary neighborhoods
• No Cargo build target selected. Set `[build] target = "wasm3

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/df876d6f3fb35b6d. Report an issue: GitHub.