pprint: infinite recursion for saferepr() when using nested objects, but str() works

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-11-04.11:44:31.577>
labels = ['type-bug', 'library', '3.9', '3.10', '3.11']
title = 'pprint: infinite recursion for saferepr() when using nested objects, but str() works'
updated_at = <Date 2022-01-03.23:47:48.417>
user = 'https://github.com/danbst'

bugs.python.org fields:

activity = <Date 2022-01-03.23:47:48.417>
actor = 'iritkatriel'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-11-04.11:44:31.577>
creator = 'danbst'
dependencies = []
files = []
hgrepos = []
issue_num = 42259
keywords = ['patch']
message_count = 4.0
messages = ['380315', '380384', '409176', '409641']
nosy_count = 4.0
nosy_names = ['serhiy.storchaka', 'iritkatriel', 'danbst', 'andrei.avk']
pr_nums = ['30256']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue42259'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']