The change made in hypothesis 6.0.4 to address a race condition works fine with pytest-httpserver on my Apple M1 laptop with Python <= 3.9, but hangs on Python 3.10 and 3.11. The problem also exists with hypothesis 6.68.2 (the latest as of this writing).

Making two calls to recursive() is all that is needed to reproduce the problem, as documented in this gist (with environment information, shell sessions, and python -vvv output diffs). It is not necessary to actually run a test, or to do anything at all with pytest-httpserver, it just needs to be installed and noticed as a plugin by pytest.

I have also filed this as csernazs/pytest-httpserver#217, as I have not even thought about threads in many years and have gone about as far as I can looking into this.