other_synchro = SIMIX_deque_get_filtered(mbox->comm_queue, SIMIX_COMM_SEND, match_fun, data, this_synchro);
if (!other_synchro) {
- XBT_DEBUG("Receive pushed first %lu", mbox->comm_queue->size());
+ XBT_DEBUG("Receive pushed first %zu", mbox->comm_queue->size());
other_synchro = this_synchro;
SIMIX_mbox_push(mbox, this_synchro);
} else {