Crash when a set is changed during iteration #68769

assignee = 'https://github.com/rhettinger'
closed_at = <Date 2015-07-07.22:32:30.674>
created_at = <Date 2015-07-07.08:09:09.600>
labels = ['interpreter-core', 'type-crash']
title = 'Crash when a set is changed during iteration'
updated_at = <Date 2015-07-08.20:03:37.466>
user = 'https://github.com/serhiy-storchaka'

activity = <Date 2015-07-08.20:03:37.466>
actor = 'python-dev'
assignee = 'rhettinger'
closed = True
closed_date = <Date 2015-07-07.22:32:30.674>
closer = 'rhettinger'
components = ['Interpreter Core']
creation = <Date 2015-07-07.08:09:09.600>
creator = 'serhiy.storchaka'
dependencies = []
files = []
hgrepos = []
issue_num = 24581
keywords = []
message_count = 5.0
messages = ['246394', '246430', '246442', '246467', '246468']
nosy_count = 3.0
nosy_names = ['rhettinger', 'python-dev', 'serhiy.storchaka']
pr_nums = []
priority = 'high'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue24581'
versions = ['Python 3.6']