on ssh server
nix-shell -i xclip
apt install xclip
on ssh server, edit ~/.tmux.conf
# To copy:
bind-key -n -t emacs-copy M-w copy-pipe "xclip -i -sel p -f | xclip -i -sel c"
# To paste:
bind-key -n C-y run "xclip -o | tmux load-buffer - ; tmux paste-buffer"
on ssh server edit ~/.emacs.el
(use-package xclip
:ensure t
:config
(xclip-mode 1))
From your ssh client, connect to tmux's ssh server.
ssh -YC my.srv