{ pytest-xdist }:
pytest-xdist.overridePythonAttrs (old: {
  patches = (old.patches or [ ]) ++ [
    ./concurrent-worker-crashes.patch
    ./worker-startup-timeout.patch
  ];

  # The suite exercises its own worker pools. Limit the outer suite to one worker.
  preCheck = builtins.replaceStrings [ "--numprocesses=$NIX_BUILD_CORES" ] [ "--numprocesses=1" ] (
    old.preCheck or ""
  );
})