Remove SelectErrorGroup

This exception is very niche, is not really intended to be caught by
the users, as it should only happen when there is something really
wrong.

If there is any unexpected error during finalization, we just raise a
`BaseExceptionGroup`, which will be automatically converted to a regular
`ExceptionGroup` by Python if there are no `BaseException`s in the
group.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -71,7 +71,6 @@
 
   - `Selected`
   - `SelectError`
-  - `SelectErrorGroup`
   - `UnhandledSelectedError`
   - `select`
   - `selected_from`
@@ -110,6 +109,8 @@
 
   This was removed alongside `Peekable` (it was only raised when using a `Receiver` that was converted into a `Peekable`).
 
+* `SelectErrorGroup` was removed, a Python built-in `BaseExceptionGroup` is raised instead in case of unexpected errors while finalizing a `select()` loop, which will be automatically converted to a simple `ExceptionGroup` when no exception in the groups is a `BaseException`.
+
 - `Timer`:
 
   - `periodic()` and `timeout()`: The names proved to be too confusing, please use `Timer()` and pass a missing ticks policy explicitly instead. In general you can update your code by doing:

src/frequenz/channels/__init__.py

@@ -58,9 +58,6 @@
 * [SelectError][frequenz.channels.SelectError]: Base class for all errors
     related to [select][frequenz.channels.select].
 
-* [SelectErrorGroup][frequenz.channels.SelectErrorGroup]: A group of errors
-    raised by [select][frequenz.channels.select].
-
 * [UnhandledSelectedError][frequenz.channels.UnhandledSelectedError]: An error
     raised by [select][frequenz.channels.select] that was not handled by the
     user.
@@ -85,7 +82,6 @@
 from ._select import (
     Selected,
     SelectError,
-    SelectErrorGroup,
     UnhandledSelectedError,
     select,
     selected_from,
@@ -103,7 +99,6 @@
     "ReceiverError",
     "ReceiverStoppedError",
     "SelectError",
-    "SelectErrorGroup",
     "Selected",
     "Sender",
     "SenderError",

src/frequenz/channels/_select.py

@@ -279,8 +279,7 @@ class SelectError(Error):
     This exception is raised when a `select()` iteration fails.  It is raised as
     a single exception when one receiver fails during normal operation (while calling
     `ready()` for example).  It is raised as a group exception
-    ([`SelectErrorGroup`][frequenz.channels.SelectErrorGroup]) when a `select` loop
-    is cleaning up after it's done.
+    ([`BaseExceptionGroup`][]) when a `select` loop is cleaning up after it's done.
     """
 
 
@@ -304,14 +303,6 @@ def __init__(self, selected: Selected[_T]) -> None:
         """The selected receiver that was not handled."""
 
 
-class SelectErrorGroup(BaseExceptionGroup[BaseException], SelectError):
-    """Some receivers stopped with errors while cleaning up a `select()` operation.
-
-    The group is composed of the errors raised by the receivers when they are stopped
-    during the cleanup of a [`select()`][frequenz.channels.select] loop.
-    """
-
-
 # Typing for select() is tricky.  We had the idea of using a declarative design for
 # select, something like:
 #
@@ -426,8 +417,8 @@ async def select(*receivers: Receiver[Any]) -> AsyncIterator[Selected[Any]]:
 
     Raises:
         UnhandledSelectedError: If a selected receiver was not handled in the if-chain.
-        SelectErrorGroup: If there is an error while finishing the select operation and
-            receivers fail while cleaning up.
+        BaseExceptionGroup: If there is an error while finishing the select operation
+            and receivers fail while cleaning up.
         SelectError: If there is an error while selecting receivers during normal
             operation.  For example if a receiver raises an exception in the `ready()`
             method.  Normal errors while receiving messages are not raised, but reported
@@ -483,7 +474,7 @@ async def _stop_pending_tasks(pending: set[asyncio.Task[bool]]) -> None:
         pending: The pending tasks to stop.
 
     Raises:
-        SelectErrorGroup: If the receivers raise any exceptions.
+        BaseExceptionGroup: If the receivers raise any exceptions.
     """
     if pending:
         for task in pending:
@@ -502,4 +493,6 @@ async def _stop_pending_tasks(pending: set[asyncio.Task[bool]]) -> None:
             # will be collected by the asyncio loop. This shouldn't be too bad as
             # errors produced by receivers will be re-raised when trying to use them
             # again.
-            raise SelectErrorGroup("Some receivers failed when select()ing", exceptions)
+            raise BaseExceptionGroup(
+                "Some receivers failed when select()ing", exceptions
+            )