Test faster, fix more

This is a bug fix release for a single bug:

  • On Windows when running two Hypothesis processes in parallel (e.g. using pytest-xdist) they could race with each other and one would raise an exception due to the non-atomic nature of file renaming on Windows and the fact that you can’t rename over an existing file. This is now fixed.


My tendency of doing immediate patch releases for bugs is unusual but generally seems to be appreciated. In this case this was a bug that was blocking a py.test merge.

I suspect this is not the last bug around atomic file creation on Windows. Cross platform atomic file creation seems to be a harder problem than I would have expected.