the tmux-new-... have been replaced with tmux-terminal-... which runs an arbitrary shell command inside a tmux pane instead of runnning a kakoune client, so tmux-new-horizontal would now be tmux-terminal-horizontal kak -c %val{session}. This was done to generalize the new alias into a terminal one.
Thanks, this is working as before with those line in kakrc ((user key) + (/ or =) to split) :
map global user / ‘:tmux-terminal-horizontal kak -c %val{session}<ret>’ -docstring ‘Split horizontal’
map global user = ‘:tmux-terminal-vertical kak -c %val{session}<ret>’ -docstring ‘Split vertical’
Do you know where we could update this information to make it more easy to set for new comers ? (the previous setting was more obvious because we just have to do the command without parameters)