After over 2 decades using GNU Screen for multiplexing, often on machines where tmux wasn’t a sensible option, I’ve realized that I’ll probably never find myself telnetting (!) into a solaris box again.
Still, tmux doesn’t “just work” the way I want with the Mac OS terminal. I am aware iterm2, wezterm, kitty and several others exist, but it’s 2025 and I’m just now migrating away from screen, so that’s the level of stodge I’m at. I still want to use the mouse to copy/paste text while I change my muscle memory from screen to tmux.
The fix, bereft of any explanation:
brew install reattach-to-user-namespace
in ~/.tmux.conf
set-option -g set-clipboard on
Then restart tmux
tmux kill-server
tmux
You have to use the fn- modifier key when selecting!! (not ⌥, as some posts suggest). Good enough for now.