The problem I identify with this is that the error creator needs to capture the backtrace for it to be useful. By the time the error has reached the application

The problem I identify with this is that the error creator needs to capture the backtrace for it to be useful. By the time the error has reached the application, the innermost parts of the stack have been popped and a backtrace is of limited usefulness. This is part of the reason that SNAFU tries to make it lightweight for library authors to add backtraces and allows application developers to turn them on.