The default command
C-b l to switch between two latest windows doesn't work on my Ubuntu 16.04.
But it works if set
bind-key l last-window after started tmux server.
I tried to set the bind key command in ~/.tmux.conf:
bind-key l last-window or
bind-key a last-window
C-b l still doesn't work, but
C-b a works.
C-b l doesn't work? How to trace the issue?