I'm currently in the job-hunting process for a new geographical area, and everyone does ask for my github account, but I'm happy to see (I don't have anything useful there) that they seem to make it just another data point and not a "gate".

The main hiring decision is made through "homework assignment", discussion around the results and good old interviews. One potential employer uses pair-programming-as-interview like Dryden suggests.

It is disturbing indeed that work on free software is used as a gateway into non-free work. I think if I am going to find a job working on free software I am going to have to create it myself. But then I first need to find the spare time to work on free software, which, as anyone can see (ha!) on my github, gitorious and gitlab accounts, I do not currently have.