Two Ctrl+C is required to terminate when a pipe is blocking

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-02-29.06:04:20.472>
labels = ['3.8', 'type-bug', '3.7', '3.9', 'expert-IO']
title = 'Two Ctrl+C is required to terminate when a pipe is blocking'
updated_at = <Date 2020-03-07.09:42:03.441>
user = 'https://github.com/msakai'

bugs.python.org fields:

activity = <Date 2020-03-07.09:42:03.441>
actor = 'terry.reedy'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['IO']
creation = <Date 2020-02-29.06:04:20.472>
creator = 'msakai'
dependencies = []
files = []
hgrepos = []
issue_num = 39792
keywords = []
message_count = 1.0
messages = ['362964']
nosy_count = 1.0
nosy_names = ['msakai']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue39792'
versions = ['Python 3.7', 'Python 3.8', 'Python 3.9']