Q&A: File source crashing with debug logs

[andrewma2]

Question

Hi, I'm seeing an issue on the newest v0.51 version where vector is crashing after trying to emit a debug log from the file source (with the debug log level turned on)

I have attached a dumbed down config, and if you run it with ./vector --config vector.json -v it will fail with the attached logs

Based off the stack trace, it seems like it's failing because that specific log line doesn't specify a rate limit or a message field? When I add a message field and rebuild, it doesn't seem to fail anymore.

Is this a bug? More generally, do we expect all logs to either specify one or the other?

Vector Config

{
	"sources": {
		"in": {
			"type": "file",
			"ignore_checkpoints": true,
			"data_dir": {SOME_DATA_DIR},
			"include": ["{A_FILE_WITH_1_2_3_SEPARATED_BY_NEWLINES"]
		}
	},
	"sinks": {
		"out": {
			"type": "console",
			"inputs": ["in"],
			"encoding": {
				"codec": "json"
			}
		}
	}
}

Vector Logs

2025-11-11T22:57:35.936304Z DEBUG vector::internal_events::file::source: Files checkpointed. count=1 duration_ms=10
2025-11-11T22:57:35.962823Z DEBUG source{component_kind="source" component_id=in component_type=file}:file_server: file_source::file_server: event_throughput=6.000/sec bytes_throughput=6.000/sec ratios={"discovery": 0.00016385377, "other": 0.00011077264, "reading": 0.0003127045, "sending": 5.2919357e-5, "sleeping": 0.9993597}
2025-11-11T22:57:36.938135Z DEBUG vector::internal_events::file::source: Internal log [Files checkpointed.] is being suppressed to avoid flooding.

thread 'vector-worker' panicked at /Users/runner/work/vector/vector/lib/tracing-limit/src/lib.rs:382:49:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0: __rustc::rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: core::option::unwrap_failed
   4: tracing_limit::RateLimitedLayer<S,L>::create_event
   5: <tracing_subscriber::layer::layered::Layered<L,S> as tracing_core::subscriber::Subscriber>::event
   6: <tracing_subscriber::layer::layered::Layered<L,S> as tracing_core::subscriber::Subscriber>::event
   7: file_source::file_server::TimingStats::report
   8: file_source::file_server::FileServer<PP,E>::run::{{closure}}
   9: tokio::runtime::task::raw::poll
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
2025-11-11T22:57:37.022564Z DEBUG vector::sources::file: Finished sending.
2025-11-11T22:57:37.022590Z DEBUG source{component_kind="source" component_id=in component_type=file}: vector::topology::builder: Source pump finished normally.
2025-11-11T22:57:37.022573Z ERROR source{component_kind="source" component_id=in component_type=file}: vector::sources::file: File server unexpectedly stopped. error=task 23 panicked with message "called `Option::unwrap()` on a `None` value" internal_log_rate_limit=false

[pront]

Hi @andrewma2, this is a known issue that will be fixed tomorrow with our patch release.