More descriptive error message than "too many values to unpack"

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-03-01.19:35:48.378>
labels = ['interpreter-core', 'type-feature', '3.9']
title = 'More descriptive error message than "too many values to unpack"'
updated_at = <Date 2021-09-02.08:29:14.157>
user = 'https://github.com/alexmojaki'

bugs.python.org fields:

activity = <Date 2021-09-02.08:29:14.157>
actor = 'nemeskeyd'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2020-03-01.19:35:48.378>
creator = 'alexmojaki'
dependencies = []
files = []
hgrepos = []
issue_num = 39816
keywords = ['patch']
message_count = 5.0
messages = ['363083', '363093', '363122', '394295', '400901']
nosy_count = 7.0
nosy_names = ['serhiy.storchaka', 'nemeskeyd', 'ZackerySpytz', 'xtreak', 'alexmojaki', 'aeros', 'malcomvx']
pr_nums = ['19036']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue39816'
versions = ['Python 3.9']