Enables or disables additional output on stderr. <level> is a positive number, with larger numbers enabling more output:
0 (= off) disables all output
1 (= on) enables only one final message about generating the result
2 enables general progress reports by the main process
3 enables detailed progress reports by the main process
4 the same, but for all processes (if multiple processes are used at all)
Levels larger than 2 may contain output that only makes sense to the developers of the Intel Trace Collector.