hashicorp/nomad · error

error tailing file: %v

Error message

error tailing file: %v

What it means

Fires in handleSingleFile when tailing (-f style): opening the log at OriginEnd with the computed offset failed, so the tail stream could not be established.

Source

Thrown at command/alloc_logs.go:304

		if nLines, nBytes := l.numLines != -1, l.numBytes != -1; nLines && nBytes {
			return errors.New("both -n and -c set")
		} else if nLines {
			offset = l.numLines * bytesToLines
		} else if nBytes {
			offset = l.numBytes
		} else {
			l.numLines = defaultTailLines
		}

		r, readErr = l.followFile(client, alloc, logType, api.OriginEnd, offset)

		// If numLines is set, wrap the reader
		if l.numLines != -1 {
			r = NewLineLimitReader(r, int(l.numLines), int(l.numLines*bytesToLines), 1*time.Second)
		}

		if readErr != nil {
			return fmt.Errorf("error tailing file: %v", readErr)
		}
	}

	defer r.Close()
	if _, err := io.Copy(os.Stdout, r); err != nil {
		return fmt.Errorf("error following logs: %s", err)
	}

	return nil
}

// followFile outputs the contents of the file to stdout relative to the end of
// the file.
func (l *AllocLogsCommand) followFile(client *api.Client, alloc *api.Allocation,
	logType, origin string, offset int64) (io.ReadCloser, error) {

	cancel := make(chan struct{})
	frames, errCh := client.AllocFS().Logs(alloc, l.follow, l.task, logType, origin, offset, cancel, nil)

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Check that the task is running and log files exist on the client
2. Verify -n/-c offset values are sensible
3. Retry; transient client streaming failures may resolve

When it happens

Trigger: Thrown at command/alloc_logs.go:304 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/2317052fba4cd470. Report an issue: GitHub.