Billionmail/BillionMail · error

create output dir: %w

Error message

create output dir: %w

What it means

TextToSpeech first ensures cfg.OutputDir exists via os.MkdirAll(dir, 0755) before writing any audio. If the directory cannot be created (permission denied, path is an existing file, read-only filesystem, invalid path), the OS error is wrapped as 'create output dir'. It is a local filesystem failure, not a Cartesia problem.

Source

Thrown at core/internal/service/video_gen/voice.go:170

	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("cartesia clone API error %d: %s", resp.StatusCode, string(body))
	}

	var result VoiceCloneResponse
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return nil, fmt.Errorf("decode clone response: %w", err)
	}
	return &result, nil
}

// TextToSpeech generates audio from text using a Cartesia voice.
// Returns the path to the output WAV file.
func TextToSpeech(ctx context.Context, cfg VoiceConfig, voiceID, transcript, filename string) (string, error) {
	if err := os.MkdirAll(cfg.OutputDir, 0755); err != nil {
		return "", fmt.Errorf("create output dir: %w", err)
	}

	req := TTSRequest{
		VoiceID:      voiceID,
		Transcript:   transcript,
		ModelID:      "sonic-2",
		OutputFormat: DefaultTTSOutputFormat(),
		Language:     "en",
	}

	httpReq, err := BuildTTSRequest(cfg, req)
	if err != nil {
		return "", err
	}
	httpReq = httpReq.WithContext(ctx)

	resp, err := cfg.doHTTP(httpReq)
	if err != nil {

View on GitHub (pinned to fc36c76c05)

Solutions

1. Check OutputDir is writable by the process user: ls -ld and touch a test file.
2. Verify OutputDir is not an existing regular file; fix the config value.
3. Ensure the container/volume is mounted read-write and has free space.
4. Create the directory ahead of time with correct ownership (mkdir -p + chown).
5. Pre-validate OutputDir in DefaultVoiceConfig / startup config checks.

Example fix

// before
if err := os.MkdirAll(cfg.OutputDir, 0755); err != nil {
    return "", fmt.Errorf("create output dir: %w", err)
}
// after
if info, err := os.Stat(cfg.OutputDir); err == nil && !info.IsDir() {
    return "", fmt.Errorf("output dir %s is a file", cfg.OutputDir)
}
if err := os.MkdirAll(cfg.OutputDir, 0o755); err != nil {
    return "", fmt.Errorf("create output dir %s: %w", cfg.OutputDir, err)
}

func ensureWritableDir(dir string) error {
    info, err := os.Stat(dir)
    if err == nil && !info.IsDir() {
        return fmt.Errorf("%s exists and is not a directory", dir)
    }
    if err := os.MkdirAll(dir, 0o755); err != nil {
        return err
    }
    probe := filepath.Join(dir, ".write-test")
    if err := os.WriteFile(probe, nil, 0o644); err != nil {
        return err
    }
    return os.Remove(probe)
}
// call before TextToSpeech:
if err := ensureWritableDir(cfg.OutputDir); err != nil {
    return fmt.Errorf("output dir unusable: %w", err)
}

path, err := video_gen.TextToSpeech(ctx, cfg, voiceID, transcript, filename)
if err != nil {
    if strings.Contains(err.Error(), "create output dir") || strings.Contains(err.Error(), "create output file") {
        log.Printf("filesystem problem with %s: %v", cfg.OutputDir, err)
        // fix config/permissions, then retry
    }
    return err
}

When it happens

Trigger: cfg.OutputDir points inside a directory the process cannot write (e.g. /root/... when running unprivileged), OutputDir path exists as a regular file, read-only container filesystem, or a path with invalid characters.

Common situations: Docker containers mounting volumes read-only, running service as non-root user while OutputDir defaults to a root-owned path, typo'd OutputDir config, disk-full or SELinux/AppArmor denial.

Understand the failure class

Background: Permission denied / not authorized / 403 Forbidden: access-control rejections when the caller lacks the required role, grant, or ownership — this error's family across 18 libraries.

Related errors

• error reading project configuration file: %v
• error writing project configuration file: %v
• error writing knowledge base file: %v
• error creating company profile file: %v
• error reading company profile file: %v

AI-assisted analysis of Billionmail/BillionMail@fc36c76c05 (2026-09-05). Data as JSON: /api/errors/3c938277e6e9c9ab. Report an issue: GitHub.