[merge][#124153][#124849] clean up capturing logging from within tests

[Vincent Ladeuil]

Vincent Ladeuil has voted comment.
Status is now: Conditionally approved
Comment:
You may want to have a look at 
test_selftest.TestTestCase.test_trace_nesting

It's not exactly the test John is describing but may be worth the 
variation.
This test is also the last one leaking a log in /tmp but I was wondering 
if your work may address that.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3Ce01316480801220007r22ceb239m106495671167b711%40mail.gmail.com%3E