I mainly have experience with git, but I assume this generalizes to other version control systems. I also think that version control is a pretty fundamental skill for software engineers (comparable to unit testing), so I think substituting that for "use a version control system to do x" would fit in with with other skills.
Generated a few comments but not many. I put in by thoughts on why code reviews are so much more better at gauging expertise. I have since adopted that and found that it led to much more productive interviews. Even candidates that do not make it thru' appreciate the fact that they were treated as peers rather than being 'questioned'.
I'd like to also add something else that I've adopted -- the solve-at-home question, if we do go with one, is never just a lazy spec. document. It is an unfinished bit of code with tests etc. This way the candidate is not intimidated/overwhelmed/have analysis-paralysis and it feels more natural. Again, insights from submission to those are better than from-scratch assignments IMO.
I use a small application that demonstrates some anti patterns / questionable design choices and ask candidates to talk me through their thoughts.