nautechsystems/nautilus_trader · error

Failed to reset file position for '{}' after {MAX_RETRIES} a

Error message

Failed to reset file position for '{}' after {MAX_RETRIES} attempts: {e}

What it means

After checking the gzip header, create_csv_reader rewinds the file to offset 0 (with retries) so the CSV reader starts from the beginning. This error is thrown when all seek attempts fail, typically because the underlying file descriptor is in an unrecoverable error state.

Source

Thrown at crates/adapters/tardis/src/csv/mod.rs:157

                );
                std::thread::sleep(Duration::from_millis(DELAY_MS));
            }
        }
    }

    if header_buf[0] != 0x1f || header_buf[1] != 0x8b {
        anyhow::bail!(
            "File '{}' has .gz extension but invalid gzip header",
            filepath_ref.display()
        );
    }

    for attempt in 1..=MAX_RETRIES {
        match file.seek(SeekFrom::Start(0)) {
            Ok(_) => break,
            Err(e) => {
                if attempt == MAX_RETRIES {
                    anyhow::bail!(
                        "Failed to reset file position for '{}' after {MAX_RETRIES} attempts: {e}",
                        filepath_ref.display()
                    );
                }
                log::warn!(
                    "Attempt {attempt}/{MAX_RETRIES} failed to seek in '{}': {e}. Retrying after {DELAY_MS}ms...",
                    filepath_ref.display()
                );
                std::thread::sleep(Duration::from_millis(DELAY_MS));
            }
        }
    }

    let buf_reader = BufReader::with_capacity(BUFFER_SIZE, file);
    let decoder = GzDecoder::new(buf_reader);

    Ok(ReaderBuilder::new()
        .has_headers(true)

View on GitHub (pinned to 18893faf8b)

Solutions

  1. Re-run the loader; transient I/O errors often resolve on retry
  2. Verify the file still exists and is readable: `ls -l` and `head -c 2 file`
  3. Re-open the file from scratch (restart the process) to get a fresh descriptor
  4. Check storage health / network mount stability if it reproduces

Example fix

// before
let reader = create_csv_reader(&path)?;  // fails after retries
// after: verify file health before loading
let metadata = std::fs::metadata(&path)?;  // errors early if file is gone
let reader = create_csv_reader(&path)?;
Defensive patterns

Strategy: retry

Validate before calling

let meta = std::fs::metadata(&path)?; // fails early if file vanished
let mut probe = std::fs::File::open(&path)?;
probe.seek(std::io::SeekFrom::Start(0))?; // exercise seek before loader

Try / catch

// retry the whole load at a higher level; internal retries already exhausted
for _ in 0..3 {
    match loader.load_trades(&path) {
        Ok(d) => break,
        Err(e) if e.to_string().contains("Failed to reset file position") => continue,
        Err(e) => return Err(e),
    }
}

Prevention

When it happens

Trigger: Calling a Tardis CSV loader where `file.seek(SeekFrom::Start(0))` fails MAX_RETRIES consecutive times — usually an I/O error on the file handle (e.g. the file was removed or the descriptor went bad after the header read).

Common situations: File on a network mount that dropped mid-open; file deleted/replaced between open and seek; disk I/O errors; extremely rare transient kernel-level failures on the descriptor.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/6289892110971865. Report an issue: GitHub.