How to find and enable Logging

Hi
I was going through documentation of ERPNext and i was unable to find the location of Logs. I just updated my bench and then it got failed with an error.
So i want track this Error. But i am not able to find Log files for it. that where the logs is going.

        https://github.com/frappe/bench/wiki

you can find log on location, frappe-bench/logs

Thanks Saurabh
Its not helpful, i am not able to see debugs which i have added in code and compiled again

Traces from bench update are not logged