[tmux] tmux set -g mouse-mode on doesn't work

You can still using the devil logic of setting options depending on your current Tmux version: see my previous answer.

But since Tmux v1.7, set-option adds "-q" to silence errors and not print out anything (see changelog). I recommend to use this feature, it's more readable and easily expandable.

Add this to your ~/.tmux.conf:

# from v2.1
set -gq mouse on
# before v2.1
set -gq mode-mouse on
set -gq mouse-resize-pane on
set -gq mouse-select-pane on
set -gq mouse-select-window on

Restar tmux or source-file your new .tmux.conf


Side note: I'm open to remove my old answer if people prefer this one