Marc-Andre Lemburg <report@bugs.python.org> wrote:
> I'm not sure how you determine what is a leak and what not.
> Interned Unicode objects stay alive until the interpreter
> is finalized.
> 
> Are you suggesting that the finalization does not free the
> interned Unicode strings or not all of them ?

No, Valgrind's "definitely lost" category means that all pointers
to an allocated region have been lost, so it would not be possible
to free the area. [1]

There are hundreds of "possibly lost" warnings as well, but I did
not report those.

My experience is that Valgrind is usually correct with "definitely
lost", see e.g. #10153. That said, of course it _could_ be a false
alarm.

[1] Last category from:

   http://mail.python.org/pipermail/python-dev/2002-October/029758.html