argNameAtPlaceholderError.lean:8:15-8:16: error: don't know how to synthesize placeholder for argument 'catchExPostpone' context: stx : Syntax ⊢ Bool argNameAtPlaceholderError.lean:8:13-8:14: error: don't know how to synthesize placeholder for argument 'expectedType?' context: stx : Syntax ⊢ Option Expr argNameAtPlaceholderError.lean:8:11-8:12: error: don't know how to synthesize placeholder for argument 'stx' context: stx : Syntax ⊢ Syntax