added condition reattach-to-user-namespace for not install environment.

.tmux.conf

@@ -58,21 +58,9 @@ set-option -g mouse-resize-pane on
 set-option -g mouse-select-window on 
 set-window-option -g mode-mouse on
 
-# tmux-powerline
-set-option -g status on
-set-option -g status-interval 2
-set-option -g status-utf8 on
-set-option -g status-left-length 60
-set-option -g status-right-length 90
-set-option -g status-left "#(~/dotfiles/tmux-powerline/powerline.sh left)"
-set-option -g status-right "#(~/dotfiles/tmux-powerline/powerline.sh right)"
-
-bind C-[ run '~/dotfiles/tmux-powerline/mute_statusbar.sh left'      # Mute left statusbar.
-bind C-] run '~/dotfiles/tmux-powerline/mute_statusbar.sh right'     # Mute right statusbar.
-
 # reattach-to-user-namespace
-set-option -g default-command "reattach-to-user-namespace -l zsh"
-bind C-q run-shell 'reattach-to-user-namespace ~/dotfiles/bin/tmux-pbcopy'
+if "test -d /usr/local/bin/reattach-to-user-namespace" "set-option -g default-command 'reattach-to-user-namespace -l zsh'"
+if "test -d /usr/local/bin/reattach-to-user-namespace" "bind C-q run-shell 'reattach-to-user-namespace ~/dotfiles/bin/tmux-pbcopy'"
 bind C-b kill-session
 
 bind-key C-i switch-client -n