If this was sarcasm and I missed it, I apologize. Because, how do you use it? How do you add debug printing to try and understand where the bug is? How do you

If this was sarcasm and I missed it, I apologize. Because, how do you use it? How do you add debug printing to try and understand where the bug is? How do you debug even anything? Like, suppose your concept has a composite requires statement that invokes a constexpr predicate of two derived types, and it is not "true" as you expected, so overload resolution picks the wrong function. What is the analog of gdb to use in this situation?