[bun] Networking errors escape as uncaught exceptions and N-API teardown can abort

[lodekeeper-z]

Describe the bug

A five-node Lodestar fleet running under Bun is healthy enough to advance and maintain peers, but it shows several runtime-specific failures in networking error handling and shutdown paths. A same-window comparison against all non-Bun beacon instances found none of the corresponding errors.

Observed on 2026-08-21 from approximately 15:35–16:18 UTC:

1. Expected network aborts escape as global uncaught exceptions

uncaughtException: The operation was aborted

• 427 occurrences across all five Bun instances in a 30-minute comparison window.
• Zero occurrences across all non-Bun beacon instances in the same window.
• Representative stack:

destroyWhenAborted (node:net:88:33)
@libp2p/utils queue/job.js
any-signal
uncaughtException

This appears related to the abort behavior previously reported in #7280, but the issue remains reproducible at fleet scale.

2. Bun network error shape breaks the req/resp peer-scoring path

TypeError: undefined is not an object
(evaluating 'e.type.error.message.includes')

Representative stack:

packages/reqresp/src/request/index.ts:160
onOutgoingReqRespError (.../network/reqresp/score.ts:41)
onOutgoingRequestError (.../ReqRespBeaconNode.ts:333)

The preceding request log renders the error as:

error=error=[object], local=true, isTrusted=false

onOutgoingReqRespError assumes e.type.error.message exists, but that field is absent for this Bun error. This occurred 16 times across four of the five Bun instances and zero times on non-Bun instances.

3. Routine socket failures escape as global uncaught exceptions

uncaughtException: recvmsg ECONNREFUSED
uncaughtException: recvmsg EHOSTUNREACH

• 13 occurrences across the Bun fleet in the 30-minute comparison window.
• Zero occurrences on non-Bun beacon instances.

These should remain handled dial/socket failures rather than reaching Lodestar's global uncaught-exception handler.

4. Native/N-API teardown can abort the process

During shutdown of one instance, after the network worker was closed and Lodestar logged terminating network worker:

assertion `left == right` failed: failed to delete napi ref
thread '<unnamed>' ... panicked at rust/lib.rs:29:1
fatal runtime error: failed to initiate panic, error 5, aborting

This was observed on one Bun instance and not on non-Bun instances in the comparison window. The immediate trigger may be in Bun or a native dependency, but it makes graceful shutdown/restart unreliable from Lodestar's perspective.

5. Lower-confidence logger/EventEmitter signal

All five Bun instances emitted:

MaxListenersExceededWarning:
Possible EventEmitter memory leak detected.
11 error listeners added to [DailyRotateFile]

No equivalent warning appeared on the non-Bun instances. This may be a Bun EventEmitter compatibility difference or a real listener leak exposed by Bun; it needs a focused Bun-vs-Node reproduction before assigning root cause.

Expected behavior

• Expected aborts and routine socket errors are handled locally and do not reach uncaughtException.
• Req/resp scoring safely handles every runtime error shape without throwing a secondary TypeError.
• Closing the network worker and native modules completes without a native abort.
• Logger transports do not accumulate unexpected listeners.

Steps to reproduce

1. Run Lodestar under Bun on a live network with normal peer churn and verbose networking logs.
2. Let the node establish a normal peer set and process req/resp traffic.
3. Observe abort and failed-dial paths for The operation was aborted, recvmsg ECONNREFUSED, and recvmsg EHOSTUNREACH reaching uncaughtException.
4. Stop/restart the node repeatedly to exercise network-worker and native/N-API teardown.
5. Compare the same workload under Node.js.

A smaller deterministic reproduction should separately cover:

• aborting a libp2p node:net operation;
• passing Bun's outgoing request error into onOutgoingReqRespError;
• repeated network-worker/native teardown;
• DailyRotateFile listener counts under Bun and Node.

Additional context

• Fleet: five Bun beacon nodes (feat1-*), four Hoodi and one Mainnet.
• Lodestar: v1.46.0/c746ec6, commit c746ec6a07a98a92c7bdb96bb410db307934f7b8.
• Runtime: Bun. The exact Bun release was not included in the collected logs; Bun reported the Node compatibility version as v26.3.0 through process.version/nodejs_version_info.
• OS: Linux.
• All five nodes remained up, advancing, and peered after the latest starts. The steady-state errors were noisy/recoverable; the teardown abort was the severe failure.
• Earlier Bun tracking issue: Running Lodestar using Bun #7280.

Suggested priority:

1. Native/N-API teardown abort.
2. Defensive handling of the error shape in onOutgoingReqRespError.
3. Escaped abort and recvmsg exceptions.
4. Bun-vs-Node logger listener comparison.