Dear Maintainer,

   * What led up to the situation?
    I have a custom ssh_config [1] that defines a not default ssh port.
When using tmate. Tmate cannot connect to ssh.tmate.io because libssh
version 9 I think doesn't parse correctly the ssh_config, it tries to use
the non default port instead of the port defined for *.io. In [2] I explain
how to reproduce the problem.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?
     Comment the ssh port option in ~/.ssh/config
     Downgrade libssh to last stable version

   * What was the outcome of this action?
      Tmate worked

   * What outcome did you expect instead?
      That tmate using libssh-4 V9 worked
# apt-get update
# apt-get install -y git wget
# apt-get build-dep -y tmate
# mkdir ~/.ssh
# cat - > ~/.ssh/config << END
# git clone https://github.com/tmate-io/tmate.git
# cd tmate/
# git checkout 2.4.0
# ./autogen.sh
# ./configure --enable-debug
# make
# ./tmate -F # This works
To connect to the session locally, run: tmate -S /tmp/tmate-0/oSLG0w attach
Connecting to ssh.tmate.io...
web session read only: https://tmate.io/t/ro-8B3p4kSE5Qz7U58Dmze4Meg5Q
ssh session read only: ssh ro-8B3p4kSE5Qz7U58Dmze4Meg5Q@lon1.tmate.io
web session: https://tmate.io/t/fzT2NfyY673DQ4PvsdMwLpSdE
ssh session: ssh fzT2NfyY673DQ4PvsdMwLpSdE@lon1.tmate.io
# ldd ./tmate | grep libssh
   libssh.so.4 => /usr/lib/x86_64-linux-gnu/libssh.so.4 (0x00007f8779e00000)
# dpkg -l | grep libssh-4
ii  libssh-4:amd64                   0.8.7-1                     amd64
   tiny C SSH library (OpenSSL flavor)
# apt-get purge -y libssh-4
# wget "
http://ftp.us.debian.org/debian/pool/main/libs/libssh/libssh-4_0.9.3-2_amd64.deb
"
# dpkg -i libssh-4_0.9.3-2_amd64.deb
# ./tmate -F # this doesn't work
./tmate -F
To connect to the session locally, run: tmate -S /tmp/tmate-0/OpKj7B attach
Connecting to ssh.tmate.io...
Error connecting: Connection refused
Reconnecting...
Connecting to ssh.tmate.io...
Error connecting: Connection refused
Reconnecting...