Slack truncates the message and therefore you cannot see all the stack traceback 

As you can see [here](https://api.slack.com/changelog/2018-04-truncating-really-long-messages) slack truncates long messages 
I was trying to limit the print_stack but I couldn't make it work
here is the documentation [print_stack](https://docs.python.org/3/library/traceback.html#traceback.print_stack)