更新到 Mojave 10.14.1 后，所有 ssh 连接失败：终端 ssh、scp、git 等，都得到一个“断管”：
ssh myserver -v
OpenSSH_7.8p1, LibreSSL 2.7.3
debug1: Reading configuration data /Users/pablo/.ssh/config
debug1: /Users/pablo/.ssh/config line 137: Applying options for myserver
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 48: Applying options for *
debug1: Connecting to myserver port 22.
debug1: Connection established.
debug1: identity file /Users/pablo/.ssh/myserver.pem type -1
debug1: identity file /Users/pablo/.ssh/myserver.pem-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.8
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6p1 Ubuntu-4ubuntu0.1
debug1: match: OpenSSH_7.6p1 Ubuntu-4ubuntu0.1 …