Comment 8 for bug 86171

Ok, this is very weird.

In the process of writing a test for this problem, I get this weird behaviour:

https://devpad.canonical.com/~andrew/paste/file2AeTTn.html

i.e. "del some_dict[some_int]" doesn't. (but repeating it does).

This happens repeatedly at the exact same point in the code every run.

With jml's help we've discovered that using the same instance of the int as reported by the dict's keys() doesn't have this behaviour, but a freshly constructed one from a literal or from thread.get_ident() will cause the buggy behaviour.

So progress on this is stalled until I can figure out why. Obviously if a key dict can't reliably have items added and removed, thing are going to go wonky.