path to zsh is hard-wired

.tmux.conf

 # General settings
 #ZSH=`which zsh`
-set-option -g default-shell /usr/local/bin/zsh
+set-option -g default-shell /bin/zsh
 set -g default-terminal "screen-256color"
 set -g history-limit 100000
 # --------- binding keys