Thanks, I found "MallocDebugReport" in `man malloc` (I could have thought to look into there...) that seem to do the trick:

$ MallocDebugReport=none ./python -m test test_decimal -m test_maxcontext_exact_arith

0:00:00 load avg: 1.27 Run tests sequentially
0:00:00 load avg: 1.27 [1/1] test_decimal

== Tests result: SUCCESS ==

1 test OK.

Total duration: 694 ms
Tests result: SUCCESS


There is also MallocDebugReport=crash that will "write messages to standard error only for a condition that is about to cause a crash." and effectively suppress this one.


Setting it in the test with os.putenv() does not seem to work.