Garbage Collection makes some object live for very long

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-12-16.10:01:34.949>
labels = ['interpreter-core', 'performance']
title = 'Garbage Collection makes some object live for very long'
updated_at = <Date 2019-12-16.19:06:33.825>
user = 'https://github.com/mistasse'

bugs.python.org fields:

activity = <Date 2019-12-16.19:06:33.825>
actor = 'pablogsal'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2019-12-16.10:01:34.949>
creator = 'mistasse'
dependencies = []
files = ['48780']
hgrepos = []
issue_num = 39061
keywords = []
message_count = 4.0
messages = ['358469', '358486', '358488', '358491']
nosy_count = 2.0
nosy_names = ['pablogsal', 'mistasse']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'resource usage'
url = 'https://bugs.python.org/issue39061'
versions = []