BoundaryML/baml · error

failed to get selected call: %w

Error message

failed to get selected call: %w

What it means

SelectedCall() fetches the currently selected LLM call via the 'selected_call' bridge method. This error wraps any failure of the bridge call itself (transport error, missing method, runtime exception), distinct from the type-assertion failure thrown right after.

Source

Thrown at engine/language_client_go/pkg/rawobjects_function_log.go:144

	result, err := raw_objects.CallMethod(f, "calls", nil)
	if err != nil {
		return nil, fmt.Errorf("failed to get calls: %w", err)
	}

	result_cast := result.([]raw_objects.RawPointer)
	calls := make([]LLMCall, len(result_cast))

	for i, call := range result_cast {
		calls[i] = call.(LLMCall)
	}

	return calls, nil
}

func (f *functionLog) SelectedCall() (LLMCall, error) {
	result, err := raw_objects.CallMethod(f, "selected_call", nil)
	if err != nil {
		return nil, fmt.Errorf("failed to get selected call: %w", err)
	}

	call, ok := result.(LLMCall)
	if !ok {
		return nil, fmt.Errorf("unexpected type for selected call: %T", result)
	}

	return call, nil
}

func (f *functionLog) Tags() (map[string]any, error) {
	result, err := raw_objects.CallMethod(f, "tags", nil)
	if err != nil {
		return nil, fmt.Errorf("failed to get tags: %w", err)
	}

	tags, ok := result.(map[string]any)
	if !ok {

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Read the wrapped root cause from the error chain
2. Verify 'selected_call' exists in the connected runtime version
3. Ensure the function has produced a call selection before querying

if flog == nil { return nil, errors.New("nil function log") }

call, err := flog.SelectedCall()
if err != nil {
    return nil, fmt.Errorf("no selected call available: %w", err)
}

When it happens

Trigger: Calling FunctionLog.SelectedCall() when the bridge call fails: the runtime object is invalid, the 'selected_call' method is absent, or the runtime raises while resolving the selected call.

Common situations: Querying selected call before the function produced/selected any call and the runtime errors instead of returning nil; runtime/runtime-binding version drift; stale disposed object handle.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• failed to get calls count: %w
• failed to get calls: %w
• failed to get tags: %w
• unexpected type for raw LLM response: %T
• failed to get text: %w

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/a99d52e31003074c. Report an issue: GitHub.