while investigating https://github.com/boto/botocore/issues/1464 I used tracemalloc (like I've done before in 3.5.2) to try to figure out where the leak was.  To my surprise tracemalloc listed stacks that didn't make any sense.


Strangest example is the top result when running the attached script against python 3.6.5 in the following manner: PYTHONMALLOC=malloc /valgrind/bin/python3 /tmp/test.py head_object

The top hit is listed as:

21 memory blocks: 4.7 KiB
  File "/tmp/test.py", line 28
    raise
  File "/tmp/test.py", line 47
    test(s3_client)
  File "/tmp/test.py", line 65
    main()

how is it that the "raise" is a leak?  It doesn't make any sense to me specially given that no contexts are used in that call.  Further that line is never hit because the exception is not re-thrown.


Further a bunch of regular expression allocs don't make any sense either given that I've cleared the cache before doing snapshots.

if someone could shed some light on why this is/isn't a bug that would be great.  It seems to me that the callstacks are not related at all to the leak.