During the backtrace after an error message, a position in interpreted code is displayed only if the load depth was at least as large at the time the code was parsed as the error depth is now. Typically, the error depth is set so that messages from code pre-interpreted and reloaded with loaddata will not appear in the backtrace.
To increase the size of the stack trace for debugging, reduce the errorDepth.
The object errorDepth is an integer.