Clearing stack frame of suspended coroutine causes coroutine to malfunction

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-12-04.08:46:49.162>
labels = ['interpreter-core', 'type-bug']
title = 'Clearing stack frame of suspended coroutine causes coroutine to malfunction'
updated_at = <Date 2020-12-04.08:46:49.162>
user = 'https://github.com/zerotypic'

bugs.python.org fields:

activity = <Date 2020-12-04.08:46:49.162>
actor = 'zerotypic'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2020-12-04.08:46:49.162>
creator = 'zerotypic'
dependencies = []
files = ['49654']
hgrepos = []
issue_num = 42566
keywords = []
message_count = 1.0
messages = ['382472']
nosy_count = 1.0
nosy_names = ['zerotypic']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue42566'
versions = ['Python 3.6']