For the Coffee Break French (a podcast that teaches French) season 3 episode 11, at the 10:15 mark, I think I hear the following:
Cette semaine, en cours, nous avons du parler de notre routine quotidienne.
I may have gotten some of the words incorrect, but I definitely hear "nous avons du parler".
I have never seen this construction before. I have seen de + infinitive before, but never du + infinitive. Can someone explain what construction is being used here, so I can Google it and learn about it?