Stack Trace

A stack trace (also called stack backtrace or stack traceback) is a report of the active stack frames at a certain point in time during the execution of a program.

It is commonly used during interactive and post-mortem debugging. It can also be displayed to the user of a program as part of an error message, which a user can report to a programmer.

A stack trace allows to track the sequence of nested functions called up to the point where the stack trace is generated. In a post-mortem scenario this is up to function where the failure occurred (but not necessarily is caused there). Sibling function calls are not visible in a stack trace.

As an example, the following Python program contains an error.

def a: b def b: c def c: error a

Running the program under the standard Python interpreter produces the following error message.

Traceback (most recent call last): File "tb.py", line 10, in a File "tb.py", line 2, in a b File "tb.py", line 5, in b c File "tb.py", line 8, in c error NameError: global name 'error' is not defined

The stack trace shows where the error occurs, namely in the c function. It also shows that the c function was called by b, which was called by a, which was in turn called by the code on line 10 (the last line) of the program.