Adding a ResourceWarning even if the generator is run to completion? That seems... dev hostile. I mean, yes, probably best to document it as best practice to use with with statement, but something simple like `files = sorted(os.scandir('.'), key=lambda x: x.stat().st_mtime)` to get files ordered by modification time (which cleanly runs the generator to exhaustion immediately) should not be raising ResourceWarning in 3.6 when it didn't do so in 3.5, and has minimal risk of leaking in any event.