Currently it seems pytest never cleans up the temporary directories it creates. Is this intended?

I can see how it can be useful when tests fail and one wants to inspect the contents of the temporary folder - but it can also cause a lot of trouble with long-running systems (I had the harddisk of a VM fill up because >2 GB of pytest tempfiles accumulated) or systems not cleaning the tempdir (Windows, I'm looking at you!).

I can think of some solutions to this:

• Add a new argument and always clean up tempdirs after a test unless that argument is given.
• Only clean up tempdirs for passing tests, and keep them for failing tests
• Clean up tempdirs after x runs (when a new run is started), or after they reached a certain age treshold.