Fix __notes__ leaking across chained exceptions (#3960)

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fixed `__notes__` from the outermost exception being shown on every exception in a chain; notes are now rendered only on the specific exception they were added to https://github.com/Textualize/rich/issues/3960
+
 ## [14.3.3] - 2026-02-19
 
 ### Fixed

CONTRIBUTORS.md

@@ -75,6 +75,7 @@ The following people have contributed to the development of Rich:
 - [Nicolas Simonds](https://github.com/0xDEC0DE)
 - [Aaron Stephens](https://github.com/aaronst)
 - [Karolina Surma](https://github.com/befeleme)
+- [Kanchan Thapa](https://github.com/kanchanthapa)
 - [Gabriele N. Tornetta](https://github.com/p403n1x87)
 - [Nils Vu](https://github.com/nilsvu)
 - [Arian Mollik Wasi](https://github.com/wasi-master)

rich/traceback.py

@@ -467,8 +467,6 @@ def extract(
 
         from rich import _IMPORT_CWD
 
-        notes: List[str] = getattr(exc_value, "__notes__", None) or []
-
         grouped_exceptions: Set[BaseException] = (
             set() if _visited_exceptions is None else _visited_exceptions
         )
@@ -481,6 +479,12 @@ def safe_str(_object: Any) -> str:
                 return "<exception str() failed>"
 
         while True:
+            # Read __notes__ from the current exception in the chain, not the
+            # outermost one. Fixes https://github.com/Textualize/rich/issues/3960
+            # where notes from the outer exception leaked onto every inner
+            # exception via the shared list reference.
+            notes: List[str] = getattr(exc_value, "__notes__", None) or []
+
             stack = Stack(
                 exc_type=safe_str(exc_type.__name__),
                 exc_value=safe_str(exc_value),

tests/test_traceback.py

@@ -375,6 +375,52 @@ def test_notes() -> None:
         assert traceback.trace.stacks[0].notes == ["Hello", "World"]
 
 
+@pytest.mark.skipif(
+    sys.version_info.minor < 11, reason="Not supported before Python 3.11"
+)
+def test_notes_isolated_per_exception_in_chain() -> None:
+    """Regression test for https://github.com/Textualize/rich/issues/3960
+
+    __notes__ added to one exception in a chain must not leak onto other
+    exceptions in the chain. Matches CPython's traceback module behavior.
+    """
+    # __cause__ chain (explicit ``raise ... from ...``)
+    try:
+        try:
+            raise ValueError("inner")
+        except ValueError as exc:
+            raise RuntimeError("outer") from exc
+    except RuntimeError as err:
+        err.add_note("note-on-outer-only")
+        traceback = Traceback()
+
+    stacks = traceback.trace.stacks
+    # stacks[0] is the outermost (RuntimeError), stacks[1] is the cause
+    # (ValueError). The note must appear only on the outer stack.
+    assert stacks[0].exc_type == "RuntimeError"
+    assert stacks[0].notes == ["note-on-outer-only"]
+    assert stacks[1].exc_type == "ValueError"
+    assert stacks[1].notes == []
+
+    # __context__ chain (implicit chaining) with a note only on the inner
+    # exception in source order (the context). The outer should have no notes.
+    try:
+        try:
+            err = ValueError("context-inner")
+            err.add_note("note-on-context-only")
+            raise err
+        except ValueError:
+            raise RuntimeError("context-outer")
+    except RuntimeError:
+        traceback = Traceback()
+
+    stacks = traceback.trace.stacks
+    assert stacks[0].exc_type == "RuntimeError"
+    assert stacks[0].notes == []
+    assert stacks[1].exc_type == "ValueError"
+    assert stacks[1].notes == ["note-on-context-only"]
+
+
 def test_recursive_exception() -> None:
     """Regression test for https://github.com/Textualize/rich/issues/3708