// Add a function to be called before each executions of comm0
// This function modifies the graph of tasks by adding or removing
// successors to comm0
- comm0->on_this_start([exec1, exec2, jupiter, fafard](simgrid::plugins::Task* t) {
+ comm0->on_this_start_cb([exec1, exec2, jupiter, fafard](simgrid::plugins::Task* t) {
auto* comm0 = dynamic_cast<simgrid::plugins::CommTask*>(t);
static int count = 0;
if (count % 2 == 0) {