What causes "failed to clear: %w" in BoundaryML/baml?

Check the unwrapped root cause (errors.Unwrap / errors.As).

failed to clear

Error message

failed to clear: %w

What it means

Go raw-objects collector error: the CallMethod('clear') invocation to clear collected logs failed at the bridge level; the %w wraps the underlying runtime error. It fires before the result is interpreted, so the count type-assertion is not the problem.

Solutions

Check the unwrapped root cause (errors.Unwrap / errors.As).
Ensure the collector belongs to the currently running runtime.
Reinstall matched BAML Go client + native binaries.

Example fix

// before
count, _ := collector.Clear()
// after
count, err := collector.Clear()
if err != nil {
	return fmt.Errorf("clear failed: %w", err)
}

Defensive patterns

Strategy: try-catch

Validate before calling

if collector == nil { return errors.New("collector not initialized") }

Try / catch

count, err := collector.Clear()
if err != nil {
	return fmt.Errorf("collector.Clear failed: %w", err)
}

Prevention

Clear collectors only while their runtime is running.
Unwrap the error chain for the native-side cause.
Reinstall matched binaries after upgrades before clearing.

When it happens

Trigger: collector.Clear() when the runtime call itself errors — stale collector pointer across runtime teardown, FFI marshalling failure, or native-side clear error.

Common situations: Clearing a collector after the BAML runtime shut down; version-skewed binaries where the 'clear' method signature changed.

Understand the failure class

Background: "API request failed": what wrapped HTTP errors from external APIs mean and how to find the real cause — this error's family across 29 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/0df4445233a03d32. Report an issue: GitHub.

Appendix: source

Thrown at engine/language_client_go/pkg/rawobjects_collector.go:115

	result, err := raw_objects.CallMethod(c, "id", map[string]any{
		"id": functionId,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to get log by id: %w", err)
	}

	log, ok := result.(FunctionLog)
	if !ok {
		return nil, fmt.Errorf("unexpected type for log by id: %T", result)
	}

	return log, nil
}

func (c *collector) Clear() (int64, error) {
	result, err := raw_objects.CallMethod(c, "clear", nil)
	if err != nil {
		return 0, fmt.Errorf("failed to clear: %w", err)
	}

	count, ok := result.(int64)
	if !ok {
		return 0, fmt.Errorf("unexpected type for clear result: %T", result)
	}

	return count, nil
}

View on GitHub (pinned to bd85ce9dee)