Observe clearer status_reason

hypothesis-python/src/hypothesis/extra/array_api.py

@@ -424,12 +424,12 @@ def do_draw(self, data):
             while elements.more():
                 i = data.draw_integer(0, self.array_size - 1)
                 if i in assigned:
-                    elements.reject()
+                    elements.reject("chose an array index we've already used")
                     continue
                 val = data.draw(self.elements_strategy)
                 if self.unique:
                     if val in seen:
-                        elements.reject()
+                        elements.reject("chose an element we've already used")
                         continue
                     else:
                         seen.add(val)

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

@@ -2273,13 +2273,13 @@ def _pop_ir_tree_node(self, ir_type: IRTypeName, kwargs: IRKWargsType) -> IRNode
         # (in fact, it is possible that giving up early here results in more time
         # for useful shrinks to run).
         if node.ir_type != ir_type:
-            self.mark_invalid()
+            self.mark_invalid(f"(internal) want a {ir_type} but have a {node.ir_type}")
 
         # if a node has different kwargs (and so is misaligned), but has a value
         # that is allowed by the expected kwargs, then we can coerce this node
         # into an aligned one by using its value. It's unclear how useful this is.
         if not ir_value_permitted(node.value, node.ir_type, kwargs):
-            self.mark_invalid()
+            self.mark_invalid(f"(internal) got a {ir_type} but outside the valid range")
 
         return node
 
@@ -2348,7 +2348,7 @@ def draw(
         strategy.validate()
 
         if strategy.is_empty:
-            self.mark_invalid("strategy is empty")
+            self.mark_invalid(f"empty strategy {self!r}")
 
         if self.depth >= MAX_DEPTH:
             self.mark_invalid("max depth exceeded")

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

@@ -809,6 +809,15 @@ def generate_new_examples(self):
 
             self.test_function(data)
 
+            if (
+                data.status == Status.OVERRUN
+                and max_length < BUFFER_SIZE
+                and "invalid because" not in data.events
+            ):
+                data.events["invalid because"] = (
+                    "reduced max size for early examples (avoids flaky health checks)"
+                )
+
             self.generate_mutations_from(data)
 
             # Although the optimisations are logically a distinct phase, we

hypothesis-python/src/hypothesis/stateful.py

@@ -478,7 +478,7 @@ def do_draw(self, data):
         machine = data.draw(self_strategy)
         bundle = machine.bundle(self.name)
         if not bundle:
-            data.mark_invalid()
+            data.mark_invalid(f"Cannot draw from empty bundle {self.name!r}")
         # Shrink towards the right rather than the left. This makes it easier
         # to delete data generated earlier, as when the error is towards the
         # end there can be a lot of hard to remove padding.

hypothesis-python/src/hypothesis/strategies/_internal/datetime.py

@@ -155,7 +155,7 @@ def do_draw(self, data):
 
         # If we happened to end up with a disallowed imaginary time, reject it.
         if (not self.allow_imaginary) and datetime_does_not_exist(result):
-            data.mark_invalid("nonexistent datetime")
+            data.mark_invalid(f"{result} does not exist (usually a DST transition)")
         return result
 
     def draw_naive_datetime_and_combine(self, data, tz):