https://mail.python.org/pipermail/python-checkins/2016-November/147171.html

test_collections leaked [0, 0, 7] memory blocks, sum=7
test_contextlib leaked [38, 38, 38] references, sum=114
test_contextlib leaked [13, 12, 12] memory blocks, sum=37
test_descr leaked [164, 164, 164] references, sum=492
test_descr leaked [59, 59, 59] memory blocks, sum=177
test_functools leaked [0, 3, 1] memory blocks, sum=4
test_with leaked [37, 37, 37] references, sum=111
test_with leaked [13, 13, 13] memory blocks, sum=39

Command line was: ['./python', '-m', 'test.regrtest', '-uall', '-R', '3:3:/home/psf-users/antoine/refleaks/reflogWMjqsJ', '--timeout', '7200']

Looking at the code change, it looks like you aren’t releasing __enter__ if the __exit__ lookup fails.

A separate question: why not swap the “async with” __aenter__ and __aexit__ code at the same time?