gh-130399: Set .name and .obj on AttributeError raised by descriptor __set__ | _PyObject_GenericSetAttrWithDict called the descriptor's tp_descr_set but never called _PyObject_SetAttributeErrorContext on failure. Every other error path in the function calls that. Adding the call provides context so a read only property provides a 'did you mean'

Author: Joekrry

Lib/test/test_traceback.py

@@ -4355,6 +4355,43 @@ class DelattrSuggestionTests(BaseSuggestionTests):
     attr_function = delattr
 
 
+class SetattrSuggestionTests(SuggestionFormattingTestMixin):
+    def get_suggestion(self, obj, attr_name=None):
+        if attr_name is not None:
+            def callable():
+                setattr(obj, attr_name, None)
+        else:
+            callable = obj
+        result_lines = self.get_exception(callable, slice_start=-1, slice_end=None)
+        return result_lines[0]
+
+    def test_property_no_setter_suggests_similar(self):
+        class A:
+            @property
+            def computed_a(self):
+                return 1
+
+            @property
+            def computed_b(self):
+                return 2
+
+            @computed_b.setter
+            def computed_b(self, val):
+                pass
+
+        actual = self.get_suggestion(A(), 'computed_a')
+        self.assertIn("Did you mean '.computed_b'", actual)
+
+    def test_property_no_setter_no_false_suggestion(self):
+        class A:
+            @property
+            def computed_a(self):
+                return 1
+
+        actual = self.get_suggestion(A(), 'computed_a')
+        self.assertNotIn("Did you mean", actual)
+
+
 class SuggestionFormattingTestBase(SuggestionFormattingTestMixin):
     def test_attribute_error_with_failing_dict(self):
         class T:
@@ -5178,6 +5215,30 @@ class CPythonDelattrSuggestionFormattingTests(
     internal traceback printing.
     """
 
+
+class PurePythonSetattrSuggestionFormattingTests(
+    PurePythonExceptionFormattingMixin,
+    SetattrSuggestionTests,
+    unittest.TestCase,
+):
+    """
+    Tests for "Did you mean" suggestions when setting a read-only property,
+    using the pure Python traceback implementation.
+    """
+
+
+@cpython_only
+class CPythonSetattrSuggestionFormattingTests(
+    CAPIExceptionFormattingMixin,
+    SetattrSuggestionTests,
+    unittest.TestCase,
+):
+    """
+    Same set of tests (for attribute setting) but with Python's internal
+    traceback printing.
+    """
+
+
 class MiscTest(unittest.TestCase):
 
     def test_all(self):

Misc/NEWS.d/next/Core_and_Builtins/2026-09-30-00-00-00.gh-issue-130399.property-setter-suggest.rst

@@ -0,0 +1,3 @@
+:exc:`AttributeError` raised when setting a read-only property now includes
+"Did you mean" suggestions, matching the behaviour already present for
+attribute lookup and deletion.

Objects/object.c

@@ -2061,6 +2061,9 @@ _PyObject_GenericSetAttrWithDict(PyObject *obj, PyObject *name,
         f = Py_TYPE(descr)->tp_descr_set;
         if (f != NULL) {
             res = f(descr, obj, value);
+            if (res < 0) {
+                _PyObject_SetAttributeErrorContext(obj, name);
+            }
             goto done;
         }
     }