pythongh-86275: use pull-through cache

.github/workflows/build.yml

@@ -396,6 +396,11 @@ jobs:
           -x test_subprocess \
           -x test_signal \
           -x test_sysconfig
+    - uses: actions/upload-artifact@v3
+      if: always()
+      with:
+        name: hypothesis-example-db
+        path: .hypothesis/examples/
 
 
   build_asan:

Lib/test/support/hypothesis_helper.py

@@ -1,3 +1,5 @@
+import os
+
 try:
     import hypothesis
 except ImportError:
@@ -11,3 +13,23 @@
         suppress_health_check=[hypothesis.HealthCheck.too_slow],
     )
     hypothesis.settings.load_profile("slow-is-ok")
+
+    # For local development, we'll write to the default on-local-disk database
+    # of failing examples, and also use a pull-through cache to automatically
+    # replay any failing examples discovered in CI.  For details on how this
+    # works, see https://hypothesis.readthedocs.io/en/latest/database.html
+    if "CI" not in os.environ:
+        from hypothesis.database import (
+            GitHubArtifactDatabase,
+            MultiplexedDatabase,
+            ReadOnlyDatabase,
+        )
+
+        hypothesis.settings.register_profile(
+            "cpython-local-dev",
+            database=MultiplexedDatabase(
+                hypothesis.settings.default.database,
+                ReadOnlyDatabase(GitHubArtifactDatabase("python", "cpython")),
+            ),
+        )
+        hypothesis.settings.load_profile("cpython-local-dev")