What causes "%s is nil" in larksuite/cli?

Identify the empty slot from the path prefix in the message (e.g. Output.Data.Shape.Items).

%s is nil

Error message

%s is nil

What it means

validateShape rejects a typedValueShape that is nil at the given JSON-pointer-like path. Shapes are built either by compileStructShape/lowerAuthoringShape or supplied explicitly via Output.Data.Shape; a nil shape means the compiler produced nothing or an authoring shape slot was left empty. It is a startup-time guard preventing a nil shape from reaching schema generation or request execution.

Source

Thrown at shortcuts/common/typed_compile_data.go:258

		if isNilCapable(field.Type) && schema.nullable == nil {
			return typedObjectShape{}, fmt.Errorf("%s field %s (%s): nil-capable field must declare nullable or nonnullable", path, field.Name, name)
		}
		description := strings.TrimSpace(field.Tag.Get("doc"))
		if input && description == "" {
			return typedObjectShape{}, fmt.Errorf("%s field %s (%s): description is required via doc", path, field.Name, name)
		}
		fieldShape, err := shapeForType(field.Type, schema, input, active)
		if err != nil {
			return typedObjectShape{}, fmt.Errorf("%s field %s (%s): %w", path, field.Name, name, err)
		}
		shape.Fields = append(shape.Fields, typedValueField{Name: name, Description: description, Required: schema.required, Shape: fieldShape})
	}
	return shape, nil
}

func validateShape(shape typedValueShape, path string) error {
	if shape == nil {
		return fmt.Errorf("%s is nil", path)
	}
	switch value := shape.(type) {
	case anyJSONShape:
	case typedStringShape:
		if value.MinLength != nil && *value.MinLength < 0 || value.MaxLength != nil && *value.MaxLength < 0 {
			return fmt.Errorf("%s string lengths must be nonnegative", path)
		}
		if value.MinLength != nil && value.MaxLength != nil && *value.MinLength > *value.MaxLength {
			return fmt.Errorf("%s minLength exceeds maxLength", path)
		}
	case typedBooleanShape:
	case typedIntegerShape:
		if value.Minimum != nil && value.Maximum != nil && *value.Minimum > *value.Maximum {
			return fmt.Errorf("%s minimum exceeds maximum", path)
		}
	case typedNumberShape:
		for _, number := range append(append([]float64{}, value.Enum...), pointerFloats(value.Minimum, value.Maximum)...) {
			if math.IsNaN(number) || math.IsInf(number, 0) {

View on GitHub (pinned to 7fd6ef3c07)

Solutions

Identify the empty slot from the path prefix in the message (e.g. Output.Data.Shape.Items).
Set the missing nested shape: every typedArrayShape must have Items, every typedOneOfShape needs non-nil variants, every object field needs a Shape.
If using an explicit Shape, prefer a struct-derived shape or a fully populated authoring shape literal.
If a custom lowering step produced nil, fix it to return a concrete shape or a descriptive error instead.

Example fix

// before
shape := typedArrayShape{} // Items left nil
// after
shape := typedArrayShape{Items: typedStringShape{MinLength: intPtr(1)}}

Defensive patterns

Strategy: validation

Validate before calling

func hasNilShapeSlot(s typedValueShape) bool {
    switch v := s.(type) {
    case typedArrayShape:
        return v.Items == nil || hasNilShapeSlot(v.Items)
    case typedOneOfShape:
        for _, variant := range v.Variants {
            if variant == nil || hasNilShapeSlot(variant) { return true }
        }
    case typedObjectShape:
        for _, f := range v.Fields {
            if f.Shape == nil || hasNilShapeSlot(f.Shape) { return true }
        }
    }
    return false
}
// call before handing the shape to the command definition
// if hasNilShapeSlot(myShape) { return errors.New("shape has nil slots") }

Type guard

func isShapeSet(s typedValueShape) bool { return s != nil }

Prevention

Always set Items on array shapes and at least two non-nil variants on oneOf shapes.
Prefer deriving shapes from Go structs via compileData instead of hand-authoring literals.
Check lowering/override helpers for paths that can silently return nil.
Add a unit test that runs validateShape over every declared command shape.

When it happens

Trigger: An explicit Output.Data.Shape (or a nested Items/Variants/field slot inside it) is nil after lowering; validateShape is called recursively (e.g. on typedArrayShape.Items or a oneOf variant) and encounters a nil entry. Also reachable via mergeInputSupplement and DataField.Shape overrides.

Common situations: Hand-authoring an Output.Data.Shape literal and leaving an Items or variant field unset; an override replaces a field with a shape that fails to lower to nil; constructing shapes programmatically where an error path silently returns nil.

Related errors

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/b5ba313bb0f9ec85. Report an issue: GitHub.