A failed target construction previously logged only reason=construction_failed and pushed an opaque "target construction failed" summary, discarding the underlying TargetError. Debugging rustfs#5115 showed the log repeated every 5s with no root cause, even though the error carried an actionable egress-policy rejection (RUSTFS_OUTBOUND_ALLOW_ORIGINS hint).
The Err branch now includes the error detail in both the error! log (detail field) and the returned failures summary. The detail is scrubbed against the instance's merged config via the loader's existing per-field redaction (secrets -> ***redacted***, endpoint URLs -> origin only, DSNs -> password masked) so credential-bearing values never reach logs or Admin-visible summaries.
A single instance with a malformed `enable` value (e.g. the typo `enable`
instead of `enabled`/`on`) made every configured notification/audit target
of every type fail to load. `create_targets_from_config_with_store_mode`
collected instance configs through the strict `try_collect_target_configs`,
whose `.collect::<Result<Vec, _>>()` short-circuits on the first error and
drops all siblings; the surrounding `?` then aborted the loop over every
plugin type.
This contradicted the function's own documented contract ("Creation is
fault-isolated per instance") and was inconsistent: target construction
failures were already isolated into the `failures` accumulator, only config
collection failures were fatal.
Add `collect_target_config_results[_from_env]`, which returns the enabled
`(id, config)` pairs plus a per-instance failure summary, and use it in the
create path. Per-instance collection errors now flow into the same
`failures`/`creation_failures` accumulator as construction failures: healthy
siblings and other target types still load, while the malformed instance is
surfaced so the notify lifecycle stays non-converged/retryable and an Admin
write cannot report a false success. Audit likewise keeps logging through
its valid targets instead of going fully Stopped.
Follow-up to #5088.
Zhengchao An