This is reachable after all

hypothesis-python/RELEASE.rst

@@ -0,0 +1,4 @@
+RELEASE_TYPE: patch
+
+Fixes :issue:`3755`, where an internal condition turns out
+to be reachable after all.

hypothesis-python/src/hypothesis/internal/conjecture/shrinker.py

@@ -570,12 +570,6 @@ def explain(self):
 
                     if result.status == Status.OVERRUN:
                         continue  # pragma: no cover  # flakily covered
-
-                    if not (
-                        len(buf_attempt_fixed) == len(result.buffer)
-                        and result.buffer.endswith(buffer[end:])
-                    ):  # pragma: no cover
-                        raise NotImplementedError("This should never happen")
                 else:
                     chunks[(start, end)].append(result.buffer[start:end])
 

hypothesis-python/tests/conjecture/test_inquisitor.py

@@ -12,6 +12,8 @@
 
 from hypothesis import given, settings, strategies as st
 
+from tests.common.utils import fails_with
+
 
 def fails_with_output(expected, error=AssertionError, **kw):
     def _inner(f):
@@ -70,3 +72,11 @@ def test_inquisitor_comments_basic_fail_if_not_all(a, b, c):
 @given(st.text(), st.text())
 def test_inquisitor_no_together_comment_if_single_argument(a, b):
     assert a
+
+
+@fails_with(ZeroDivisionError)
+@settings(database=None)
+@given(start_date=st.datetimes(), data=st.data())
+def test_issue_3755_regression(start_date, data):
+    data.draw(st.datetimes(min_value=start_date))
+    raise ZeroDivisionError