asyncio.TaskGroup keeps references to errors after raising ExceptionGroup

[kumaraditya303]

asyncio.TaskGroup keeps references to errors after raising ExceptionGroup. This is because it keeps a ref to list of errors in errors local and since this local is kept alive by frame via traceback, this causes ref cycles. The correct fix is to use self._errors directly and then assign None to it in finally.

cpython/Lib/asyncio/taskgroups.py

Lines 127 to 135 in 8d57423

	if self._errors:
	# Exceptions are heavy objects that can have object
	# cycles (bad for GC); let's not keep a reference to
	# a bunch of them.
	errors = self._errors
	self._errors = None
	me = BaseExceptionGroup('unhandled errors in a TaskGroup', errors)
	raise me from None

[kumaraditya303]

Fixed by #98544