> Does the ? operator add some kind of stack trace
It depends. `?` will convert the inner error type (the value from the function to its left) to the outer error type (the return type of the function containing this line). That conversion function can be defined by the inner error type. If the conversion generates a stack trace (or adds to an existing one), then there will be one.
Therefore, "Is there always a stack trace available?" is a tricky question-- it was seen as unimportant during the 1.0 days because they wanted to be able to accommodate low-resource environments.
Today, there's third party error handling libraries that cut out error creation / manipulation boilerplate, that might create stack traces for you, and there's efforts ongoing to see how it might be added to the stdlib.
It depends. `?` will convert the inner error type (the value from the function to its left) to the outer error type (the return type of the function containing this line). That conversion function can be defined by the inner error type. If the conversion generates a stack trace (or adds to an existing one), then there will be one.
Therefore, "Is there always a stack trace available?" is a tricky question-- it was seen as unimportant during the 1.0 days because they wanted to be able to accommodate low-resource environments.
Today, there's third party error handling libraries that cut out error creation / manipulation boilerplate, that might create stack traces for you, and there's efforts ongoing to see how it might be added to the stdlib.