What causes "timeout cannot be negative" in Tencent/WeKnora?

Set DefaultTimeout to a positive duration (e.g. 30 * time.Second) or leave it at zero for no default.

timeout cannot be negative

Error message

timeout cannot be negative

What it means

ValidateConfig rejects a SandboxConfig whose DefaultTimeout is negative. Timeouts must be zero (no default) or positive; a negative value indicates a computation or config parsing bug, so Manager creation refuses to proceed.

Source

Thrown at internal/sandbox/sandbox.go:378

		CubeHTTPTimeout: DefaultCubeHTTPTimeout,
	}
}

// ValidateConfig validates sandbox configuration
func ValidateConfig(config *Config) error {
	if config == nil {
		return errors.New("config is nil")
	}

	switch config.Type {
	case SandboxTypeDocker, SandboxTypeCube, SandboxTypeE2B, SandboxTypeDisabled:
		// Valid types
	default:
		return errors.New("invalid sandbox type")
	}

	if config.DefaultTimeout < 0 {
		return errors.New("timeout cannot be negative")
	}

	if config.MaxMemory < 0 {
		return errors.New("memory limit cannot be negative")
	}

	if config.MaxCPU < 0 {
		return errors.New("CPU limit cannot be negative")
	}

	return nil
}

View on GitHub (pinned to 988cbb0330)

Solutions

Set DefaultTimeout to a positive duration (e.g. 30 * time.Second) or leave it at zero for no default.
Audit where the value is computed — fix any time.Since/time.Until mixup producing negatives.
Validate DefaultTimeout >= 0 before constructing the Manager and fail fast with context.

Example fix

// before
cfg.DefaultTimeout = time.Until(deadline) // negative if deadline passed
// after
if d := time.Until(deadline); d > 0 {
    cfg.DefaultTimeout = d
} else {
    cfg.DefaultTimeout = 30 * time.Second
}

Defensive patterns

Strategy: validation

Validate before calling

if cfg.DefaultTimeout < 0 {
    return fmt.Errorf("invalid sandbox config: DefaultTimeout=%v must be >= 0", cfg.DefaultTimeout)
}

Try / catch

if err := sandbox.ValidateConfig(cfg); err != nil {
    if strings.Contains(err.Error(), "timeout") {
        cfg.DefaultTimeout = 30 * time.Second // safe default
        return nil
    }
    return err
}

Prevention

Use time.Duration typed fields everywhere; avoid raw ints.
Never assign the result of time.Since as a timeout; use time.Until with a positivity check.
Validate configs in unit tests.

When it happens

Trigger: Passing a SandboxConfig with DefaultTimeout < 0 to NewManager or NewSessionBoundManager, e.g. from subtracting timestamps, misreading duration units, or a negative number in a config file.

Common situations: Loading YAML/JSON config with a negative timeout; computing a deadline with time.Since instead of time.Until and storing the negative result.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of Tencent/WeKnora@988cbb0330 (2026-09-02). Data as JSON: /api/errors/f0abfd17126ab8bd. Report an issue: GitHub.