I have several terminal emulators installed on my Mac: kitty, Alacritty and iterm2. When I start a Tmux session in Alacritty and try to create another tmux session in kitty, I noticed this strange error that I have never met before:

open terminal failed: missing or unsuitable terminal: xterm-kitty

For clarity, kitty seems to use its own terminfo file called xterm-kitty, and Alacritty and iterm2 both use the good-old xterm-256color.

The author of kitty claims that:

tmux does not support multiple terminfo. You will need to kill all existing tmux sessions and start a new one.

I find his claim to be partly true. If I create a session in Alacritty, I can not attach to this session or create new session in kitty. However, if I initially create a new session (before that, there is not tmux session running) in kitty, I can indeed attach to that session or create a new session in Alacritty.

My version info:

  • kitty: 0.17.2
  • Alacritty: 0.4.0
  • Tmux: 3.1b

So my temporary solution is to kill all sessions in other terminal emulators if you want to use tmux in kitty.

Tmux error when sshing to remote server

If you ssh to another server using kitty terminal and met this issue when starting tmux on that server. The reason may be that xterm-kitty terminfo file may not be available on that server. You can use the following command to copy the terminfo file to the remote server as indicate here:

kitty +kitten ssh myserver