Live preflight at 2026-08-18T08:42Z surfaced a real entry in error.log:
[2026-08-18T06:49:03.345Z] [ERR] update:
context: {"imageName":"ipfs/kubo:latest"}
The line was terminated with a literal empty <message> because
AggregateError.message is empty by spec — registry-1.docker.io multi-A
timeouts (and any Promise.any / multi-fetch failure) leaked through with
no actionable signal. The only clue was a JSON context tail, and even that
didn't say WHY. Operators / incident-triage scripts that grep error.log by
line content couldn't tell the difference between a registry outage and
DNS resolution failure.
**Fix** (dashcaddy-api/src/utils/logging.js, +70 lines):
- describeErrorChain(err, depth, seen) flattens .errors[] (AggregateError)
and .cause chains into readable lines, each carrying Name [CODE]: message.
- writeErrorLog builds both the headline (replacing bare error.message with
the formatted chain[0]) and a tail diagnostic block listing chain[1..].
Backwards-compat preserved: headline still matches [ERR] ${ctx}: <head>.
- Cycle guard via WeakSet seen: pathological err.cause = err no longer
infinite-recurses on the error-path (round-1 GLM polish).
- Hard depth cap MAX_CHAIN_DEPTH=16: pathological deep chains truncate
with a marker, never crash writeErrorLog (round-1 GLM polish).
- Defensive head line for empty err.message: falls back to error.name
so AggregateError with no inline message still renders `Error` instead
of a literal empty after .
**Tests** (__tests__/utils-logging-aggregate-error.test.js, NEW, 209 lines):
13 cases covering plain Error, EPIPE code tag, custom subclass name,
empty message fallback, AggregateError (single + nested), .cause chain,
req field, extra JSON, separator invariant, circular .cause, depth-truncation,
circular .errors[].
GLM judge round 1 (deleg_59155c78, 43.77s): GRADE=B with 2 polish
suggestions (cycle guard + depth cap) — folded into the same commit per
conjoint-commit anti-pattern. Round 2: not needed (the polish is in).
Full suite: 89 suites / 1975 tests pass (+13 net new). ESLint clean.
Hermes
3137d4c16d