This is necessary only for backwards compatibility for tmux 1.8 running on Ubuntu 14.04. The problem does not exist on Ubuntu 18.04 or cygwin.
Specifically
tmux new-window -n ancillary-window command -with -args
needs to become
tmux new-window -n ancillary-window 'command -with -args'
The same is true for split-window commands.
This is necessary only for backwards compatibility for tmux 1.8 running on Ubuntu 14.04. The problem does not exist on Ubuntu 18.04 or cygwin.
Specifically
tmux new-window -n ancillary-window command -with -args
needs to becometmux new-window -n ancillary-window 'command -with -args'
The same is true forsplit-window
commands.