From b74af41db76040b680407a07a23e0413fa238f79 Mon Sep 17 00:00:00 2001
From: mariosasko <mariosasko777@gmail.com>
Date: Thu, 17 Oct 2024 16:00:16 +0200
Subject: [PATCH 1/3] Fix error notes removal in enum initialization

---
 Lib/enum.py           | 16 +++++-----------
 Lib/test/test_enum.py | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/Lib/enum.py b/Lib/enum.py
index 17d72738792982..0a1b9fb3f34cca 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -554,22 +554,16 @@ def __new__(metacls, cls, bases, classdict, *, boundary=None, _simple=False, **k
         classdict['_all_bits_'] = 0
         classdict['_inverted_'] = None
         try:
-            exc = None
             classdict['_%s__in_progress' % cls] = True
             enum_class = super().__new__(metacls, cls, bases, classdict, **kwds)
             classdict['_%s__in_progress' % cls] = False
             delattr(enum_class, '_%s__in_progress' % cls)
         except Exception as e:
-            # since 3.12 the line "Error calling __set_name__ on '_proto_member' instance ..."
-            # is tacked on to the error instead of raising a RuntimeError
-            # recreate the exception to discard
-            exc = type(e)(str(e))
-            exc.__cause__ = e.__cause__
-            exc.__context__ = e.__context__
-            tb = e.__traceback__
-        if exc is not None:
-            raise exc.with_traceback(tb)
-        #
+            # since 3.12 the note "Error calling __set_name__ on '_proto_member' instance ..."
+            # is tacked on to the error instead of raising a RuntimeError, so discard it
+            if hasattr(e, '__notes__'):
+                del e.__notes__
+            raise
         # update classdict with any changes made by __init_subclass__
         classdict.update(enum_class.__dict__)
         #
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 5b4a8070526fcf..ba34522921d273 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1888,6 +1888,26 @@ def test_wrong_inheritance_order(self):
             class Wrong(Enum, str):
                 NotHere = 'error before this point'
 
+    def test_raise_custom_error_on_creation(self):
+        class InvalidRgbColorError(ValueError):
+            def __init__(self, r, g, b):
+                self.r = r
+                self.g = g
+                self.b = b
+                super().__init__(f'({r}, {g}, {b}) is not a valid RGB color')
+
+        with self.assertRaises(InvalidRgbColorError):
+            class RgbColor(Enum):
+                RED = (255, 0, 0)
+                GREEN = (0, 255, 0)
+                BLUE = (0, 0, 255)
+                INVALID = (256, 0, 0)
+
+                def __init__(self, r, g, b):
+                    rgb = (r, g, b)
+                    if not all(0 <= val <= 255 for val in rgb):
+                        raise InvalidRgbColorError(*rgb)
+
     def test_intenum_transitivity(self):
         class number(IntEnum):
             one = 1

From 054c300bed60d5920b7326b1bd445f5874ab5acf Mon Sep 17 00:00:00 2001
From: mariosasko <mariosasko777@gmail.com>
Date: Thu, 17 Oct 2024 16:39:27 +0200
Subject: [PATCH 2/3] Nit

---
 Lib/test/test_enum.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index ba34522921d273..19dff3980cbb14 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1904,9 +1904,8 @@ class RgbColor(Enum):
                 INVALID = (256, 0, 0)
 
                 def __init__(self, r, g, b):
-                    rgb = (r, g, b)
-                    if not all(0 <= val <= 255 for val in rgb):
-                        raise InvalidRgbColorError(*rgb)
+                    if not all(0 <= val <= 255 for val in (r, g, b)):
+                        raise InvalidRgbColorError(r, g, b)
 
     def test_intenum_transitivity(self):
         class number(IntEnum):

From d185ebd8364c7b0422411bfc29b3d88b517e279e Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Thu, 17 Oct 2024 16:10:30 +0000
Subject: [PATCH 3/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/Library/2024-10-17-16-10-29.gh-issue-125259.oMew0c.rst  | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-10-17-16-10-29.gh-issue-125259.oMew0c.rst

diff --git a/Misc/NEWS.d/next/Library/2024-10-17-16-10-29.gh-issue-125259.oMew0c.rst b/Misc/NEWS.d/next/Library/2024-10-17-16-10-29.gh-issue-125259.oMew0c.rst
new file mode 100644
index 00000000000000..4fa6330abea512
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-17-16-10-29.gh-issue-125259.oMew0c.rst
@@ -0,0 +1 @@
+Fix the notes removal logic for errors thrown in enum initialization.