Thanks to who all who responded and commented!
I am yes, but. Yes, but the penalty should be small. The infrastructure should make it easy to vote, with features like a statutory holiday for election day, mail-in voting, and electronic voting.
@evan I am much more strongly opposed to electronic voting than to compulsory voting.
Canada has at present a voting system that is fast, reliable, simple and well-trusted. The reason for the latter is that voters, even disappointed ones, can easily understand how the system works, and outsiders can verify it. It would be a terrible mistake to move to electronic voting, one that we'd regret within a few election cycles.
Evan Prodromou
Eric G.
G.I. Robot 
M. Grégoire