Tracing events "SR" not available without MSG.
The tracing events "SR" (matching sends with receives) are only available with MSG.
I open this issue to discuss if this should be developed for S4U, or simply lost when MSG will go.
The change has been seen when converting the trace-process-migration
example from MSG to S4U (see commit
295e4684)
The feature is currently implemented in functions simgrid::msg::Task::send_async() and MSG_task_receive_with_timeout_bounded().