Hi everyone, In gambit, when dealing with macros, it became hard to debug because the source information got lost in expander so we couldn't generate good debug information. For gambit's internal macros, it mostly use the ##define-syntax to acquire source-object instead of stripped s-expression. It's doable with lisp style macros, (though it need more work to reimplement your original macros.) But things became hard to deal with if taking hygienic macros into consideration, as syntax-rules expander will apply pattern match to the s-expression. I was wondering if there's any possibilities that make source objects completely transparently to the macro expander, for example: test.scm: (define-syntax test ;; x passed in as a source object (syntax-rules () ((_ x) (pp (syntax-location x))))) (test 3) output: File: test.scm, Line: ... I've thought following solutions: 1. Make custom exception handlers for type-exception, and recall the procedure if we found the callee args is an source-object. primitives like car, cdr will work directly pros: No need to do internal changes. cons: type-exception will not be raised by functions take general parameters, like pp, pair?, list? 2. Adding a new subtype, and let every primitives call it as-is. pros: The whole system worked as is, there's a similar solution for promise auto-force in gambit so we can refer from. cons: This will added possible load to runtime system.(every primitives have to check this type and unbox it). As I'm not an expert to gambit's internal implementation, I would like to ask if there's other possible solution to this problem? Thanks Meng