Kuberwastaken/claurst · critical

Failed to build reqwest client

Error message

Failed to build reqwest client

What it means

This panic comes from an `.expect()` on `reqwest::Client::builder().build()` when constructing the bridge's HTTP client (30s timeout, claude-code-rust user agent). The builder only fails on process-wide initialization problems, essentially always TLS backend setup, so the code treats it as unrecoverable during `Bridge::new`.

Solutions

  1. Verify TLS linkage: run `ldd` on the binary and install the missing `libssl`/crypto library, or build with reqwest's `rustls-tls` feature instead of native-tls.
  2. Install CA certificates in the deployment image (`ca-certificates` package).
  3. Check for conflicting `CryptoProvider` initializers if using rustls 0.23+ (only one process-wide provider may be installed).
  4. Make `Bridge::new` return `Result` and propagate the `reqwest::Error` with context rather than panicking.

Example fix

// before
.build()
.expect("Failed to build reqwest client");
// after
.build()
.map_err(|e| BridgeError::Init(format!("Failed to build reqwest client: {e}")))?;
Defensive patterns

Strategy: fallback

Validate before calling

// Startup probe before creating the Bridge:
fn http_stack_ok() -> bool {
    reqwest::Client::builder()
        .timeout(std::time::Duration::from_secs(1))
        .build()
        .is_ok()
}

Try / catch

// Panic, not Result — isolate construction:
let bridge = std::panic::catch_unwind(|| Bridge::new(config, session_id))
    .map_err(|_| anyhow::anyhow!("bridge init failed: cannot build HTTP client (TLS backend?)"))?;

Prevention

When it happens

Trigger: Calling `Bridge::new(config, session_id)` in a process where reqwest cannot initialize its TLS backend — e.g. missing native TLS library or rustls crypto provider conflict.

Common situations: Minimal Linux containers without libssl or CA certs; statically-linked musl builds missing TLS pieces; environments where another component already installed a different ring/aws-lc crypto provider for rustls.

Related errors

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/d684886b96c81751. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/bridge/src/lib.rs:411

    state: Arc<RwLock<BridgeState>>,
    http: reqwest::Client,
    reconnect_count: u32,
    #[allow(dead_code)]
    last_ping: Option<std::time::Instant>,
}

impl BridgeSession {
    /// Create a new bridge session; generates a fresh UUID for `session_id`.
    pub fn new(config: BridgeConfig) -> Self {
        let session_id = uuid::Uuid::new_v4().to_string();
        let http = reqwest::Client::builder()
            .timeout(std::time::Duration::from_secs(30))
            .user_agent(format!(
                "claude-code-rust/{}",
                env!("CARGO_PKG_VERSION")
            ))
            .build()
            .expect("Failed to build reqwest client");

        Self {
            config,
            session_id,
            state: Arc::new(RwLock::new(BridgeState::Connecting)),
            http,
            reconnect_count: 0,
            last_ping: None,
        }
    }

    pub fn session_id(&self) -> &str {
        &self.session_id
    }

    pub fn current_state(&self) -> BridgeState {
        self.state.read().clone()
    }

View on GitHub (pinned to b0637c97ec)