Let there be three cdi projects: p1 depends on p2 and p3; p2 depends on p3. All dependencies are explicit. When change in p3 takes place, builder of p3 calls update for dependent projects p1, p2. Now update is implemented recurrently: update of p2 will call update of projects that depend on it, hence update of p1 will be called twice. If there are N projects in similar hierarchy, when the top project is modified, update of the bottom project will be called 2^(N - 2) times. Instead, we should remove recurrence and just collect projects that should be updated.