Whatever the command line options connection sharing configured in
~/.ssh/config stays somehow active, and cause errors.
Ansible has custom code to detect the situation and automatically
restart a SSH connection (see AnsibleControlPersistBrokenPipeError usage
in lib/ansible/plugins/connection/ssh.py, also relevant is bug#16731).
The only reliable fix is thus to change ~/.ssh/config to limit
connection sharing to apply to some hosts only.
Frédéric Péters
5e506bcbd4