python3Packages.hypothesis: fix downstream flaky test failures

pkgs/development/python-modules/hypothesis/default.nix

@@ -27,7 +27,7 @@ buildPythonPackage rec {
   version = "6.130.12";
   pyproject = true;
 
-  disabled = pythonOlder "3.7";
+  disabled = pythonOlder "3.9";
 
   src = fetchFromGitHub {
     owner = "HypothesisWorks";
@@ -66,20 +66,40 @@ buildPythonPackage rec {
 
   inherit doCheck;
 
-  # This file changes how pytest runs and breaks it
+  # tox.ini changes how pytest runs and breaks it.
+  # Activate the CI profile (similar to setupHook below)
+  # by setting HYPOTHESIS_PROFILE [1].
+  #
+  # [1]: https://github.com/HypothesisWorks/hypothesis/blob/hypothesis-python-6.130.9/hypothesis-python/tests/common/setup.py#L78
   preCheck = ''
     rm tox.ini
+    export HYPOTHESIS_PROFILE=ci
   '';
 
   pytestFlagsArray = [ "tests/cover" ];
 
+  # Hypothesis by default activates several "Health Checks", including one that fires if the builder is "too slow".
+  # This check is disabled [1] if Hypothesis detects a CI environment, i.e. either `CI` or `TF_BUILD` is defined [2].
+  # We set `CI=1` here using a setup hook to avoid spurious failures [3].
+  #
+  # Example error message for reference:
+  # hypothesis.errors.FailedHealthCheck: Data generation is extremely slow: Only produced 2 valid examples in 1.28 seconds (1 invalid ones and 0 exceeded maximum size). Try decreasing size of the data you're generating (with e.g. max_size or max_leaves parameters).
+  #
+  # [1]: https://github.com/HypothesisWorks/hypothesis/blob/hypothesis-python-6.130.9/hypothesis-python/src/hypothesis/_settings.py#L816-L828
+  # [2]: https://github.com/HypothesisWorks/hypothesis/blob/hypothesis-python-6.130.9/hypothesis-python/src/hypothesis/_settings.py#L756
+  # [3]: https://github.com/NixOS/nixpkgs/issues/393637
+  setupHook = ./setup-hook.sh;
+
   disabledTests =
     [
       # racy, fails to find a file sometimes
       "test_recreate_charmap"
       "test_uses_cached_charmap"
-      # fails if builder is too slow
-      "test_can_run_with_no_db"
+      # fail when using CI profile
+      "test_given_does_not_pollute_state"
+      "test_find_does_not_pollute_state"
+      "test_does_print_on_reuse_from_database"
+      "test_prints_seed_only_on_healthcheck"
       # calls script with the naked interpreter
       "test_constants_from_running_file"
     ]
@@ -122,14 +142,16 @@ buildPythonPackage rec {
     };
   };
 
-  meta = with lib; {
+  meta = {
     description = "Library for property based testing";
     mainProgram = "hypothesis";
     homepage = "https://github.com/HypothesisWorks/hypothesis";
     changelog = "https://hypothesis.readthedocs.io/en/latest/changes.html#v${
       lib.replaceStrings [ "." ] [ "-" ] version
     }";
-    license = licenses.mpl20;
-    maintainers = [ ];
+    license = lib.licenses.mpl20;
+    maintainers = [
+      lib.maintainers.fliegendewurst
+    ];
   };
 }

pkgs/development/python-modules/hypothesis/setup-hook.sh

@@ -0,0 +1,5 @@
+hypothesisActivateProfileForCI() {
+    export CI=1
+}
+
+postHooks+=(hypothesisActivateProfileForCI)