Returns a string with a traceback of the stack call. An optional message string is prepended to the beginning of the traceback message.
function f ()
function g ()
print (debug.traceback ("traceback in g"))
end -- g
g ()
end -- f
f ()
-->
traceback in g
stack traceback:
stdin:3: in function `g'
stdin:6: in function `f'
stdin:1: in main chunk
[C]: ?
You can optionally supply a thread (coroutine) to be traced. This is useful if you get an error after calling coroutine.resume.
An optional level number tells at which level to start the tracekback - the default is 1 which is the function calling traceback.