nautechsystems/nautilus_trader · error

validated proxy target hash

Error message

validated proxy target hash

What it means

This panic occurs in verify_deployment_manifest when parsing proxy.target_code_hash into a B256 via expect(). The manifest is supposed to have been validated (well-formed hex hashes/addresses) before verification, so an unparseable value indicates the caller bypassed or defeated that validation. It is an internal invariant guard, not a runtime network error.

Source

Thrown at crates/adapters/blockchain/src/rpc/verification.rs:681

                        );
                    }
                    VerificationOutcome::Disagreement(failure) => {
                        return VerificationOutcome::Disagreement(failure);
                    }
                    VerificationOutcome::Unavailable(failure) => {
                        return VerificationOutcome::Unavailable(failure);
                    }
                    VerificationOutcome::Retryable(failure) => {
                        return VerificationOutcome::Retryable(failure);
                    }
                    VerificationOutcome::LocallyInvalid(failure) => {
                        return VerificationOutcome::LocallyInvalid(failure);
                    }
                }
                let target =
                    Address::from_str(&proxy.target_address).expect("validated proxy target");
                let target_hash =
                    B256::from_str(&proxy.target_code_hash).expect("validated proxy target hash");
                match self.verify_code(&target, block).await {
                    VerificationOutcome::Verified(verified)
                        if !verified.value.is_empty()
                            && keccak256(&verified.value) == target_hash => {}
                    VerificationOutcome::Verified(_) => {
                        return VerificationOutcome::Disagreement(
                            self.failure(VerificationRead::DeploymentIdentity),
                        );
                    }
                    VerificationOutcome::Disagreement(failure) => {
                        return VerificationOutcome::Disagreement(failure);
                    }
                    VerificationOutcome::Unavailable(failure) => {
                        return VerificationOutcome::Unavailable(failure);
                    }
                    VerificationOutcome::Retryable(failure) => {
                        return VerificationOutcome::Retryable(failure);
                    }

View on GitHub (pinned to 18893faf8b)

Solutions

1. Run the manifest through its validation/normalization step before calling verify_deployment_manifest
2. Check proxy.target_code_hash: it must parse as a 32-byte hex string (e.g. via B256::from_str in a test)
3. Re-generate the manifest from the deployment tooling instead of hand-editing
4. If the validator accepts but the parser rejects, file a bug: the validator is missing a target_code_hash format check

Example fix

// before
let manifest: BlockchainDeploymentManifest = serde_json::from_str(&raw).unwrap();
client.verify_deployment_manifest(&manifest, block).await;
// after
let manifest = validate_manifest(&raw)?; // rejects malformed target_code_hash early
client.verify_deployment_manifest(&manifest, block).await;

fn validate_proxy_target(proxy: &ProxyConfig) -> Result<(), String> {
    B256::from_str(&proxy.target_code_hash)
        .map(|_| ())
        .map_err(|e| format!("invalid target_code_hash '{}': {e}", proxy.target_code_hash))
}

fn is_valid_code_hash(s: &str) -> bool {
    let h = s.trim_start_matches("0x");
    h.len() == 64 && h.chars().all(|c| c.is_ascii_hexdigit())
}

When it happens

Trigger: Calling verify_deployment_manifest with a hand-constructed or deserialized BlockchainDeploymentManifest whose proxy.target_code_hash is empty, malformed, or not 32-byte hex (with or without 0x prefix).

Common situations: Loading a manifest from a hand-edited JSON file; a schema change or new manifest version not run through the validator; a proxy entry pointing at a target whose code hash was recorded as a placeholder (e.g. zeros or a transaction hash instead of a code hash).

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• validated manifest probe data
• validated manifest probe output
• validated proxy target address
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AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/af2fc4bfa606e260. Report an issue: GitHub.