Bug report

Since about 4 days ago, test_perf_profiler.test_python_calls_appear_in_the_stack_if_perf_activated usually fails on refleaks buildbots with one of these (see build 416 for both):

• AssertionError: 'py::foo:/tmp/test_python_2wtkitdm/tmpv30razor/perftest.py' not found in <very long string containing frames with a different temp dir instead: /tmp/test_python_ecqze28x/tmpz61vpvo4/perftest.py+0xb here>
• unexpected stderr:

  Warning:
  Processed 688 events and lost 3 chunks!
  
  Check IO/CPU overload!