I've never asked for or looked at anyone's github or personal code as part of a job interview. Too easy to fake, and too much risk that it's something proprietary that could put me in a bad spot.
Huh? Proprietary code sometimes leaks on GitHub, but open source code hosted on GitHub is the opposite of proprietary. What bad spot are you going to get into?
Often times, candidates are currently employed, likely at a competitor. Any code they write can potentially be claimed as a work product and I want no part of that possibility.