Explain mode requires shrinking

Zac-HD · Zac-HD · commit f6fc69fb9868 · 2021-06-09T22:25:12.000+10:00
With shrinking disabled you get *a* result, but the "always observed for failing examples" part is pretty vacuous.
diff --git a/hypothesis-python/RELEASE.rst b/hypothesis-python/RELEASE.rst
@@ -0,0 +1,4 @@
+RELEASE_TYPE: minor
+
+The :ref:`explain phase <phases>` now requires shrinking to be enabled,
+and will be automatically skipped for deadline-exceeded errors.
diff --git a/hypothesis-python/src/hypothesis/core.py b/hypothesis-python/src/hypothesis/core.py
@@ -670,6 +670,7 @@ def _execute_once_for_engine(self, data):
             if (
                 self.failed_normally
                 and not self.failed_due_to_deadline
+                and Phase.shrink in self.settings.phases
                 and Phase.explain in self.settings.phases
                 and sys.gettrace() is None
                 and not PYPY
