grafana/k6 · error

flushing data to disk: %w

Error message

flushing data to disk: %w

What it means

Error "flushing data to disk: %w" thrown in grafana/k6.

Source

Thrown at internal/js/modules/k6/browser/storage/file_persister.go:49

	f, err := os.OpenFile(cp, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o600) //nolint:forbidigo
	if err != nil {
		return fmt.Errorf("creating a local file %q: %w", cp, err)
	}
	defer func() {
		if cerr := f.Close(); cerr != nil && err == nil {
			err = fmt.Errorf("closing the local file %q: %w", cp, cerr)
		}
	}()

	bf := bufio.NewWriter(f)

	if _, err := io.Copy(bf, data); err != nil {
		return fmt.Errorf("copying data to file: %w", err)
	}

	if err := bf.Flush(); err != nil {
		return fmt.Errorf("flushing data to disk: %w", err)
	}

	return nil
}

// RemoteFilePersister is to be used when files created by the browser module need
// to be uploaded to a remote location. This uses a presignedURLRequestURL to
// retrieve one presigned URL. The presigned url is used to upload the file
// to the remote location.
type RemoteFilePersister struct {
	presignedURLRequestURL string
	headers                map[string]string
	basePath               string

	httpClient *http.Client
}

// PresignedURLResponse holds the response from a presigned generation request.

View on GitHub (pinned to 93accf6570)

When it happens

Trigger: Thrown at internal/js/modules/k6/browser/storage/file_persister.go:49 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/e54dde435b4ce045. Report an issue: GitHub.