UPDATE: macOS 14 (Sonoma) updated its bundled ncurses version to 6.0. This version ships with a tmux-256color entry by default, so the workaround below is no longer needed. macOS ships with an old and very out-of-date version of ncurses (5.7). This version does not contain a terminfo entry for tmux-256color, the preferred TERM value when using tmux. If you installed tmux via Homebrew or MacPorts, then you will also have a newer version of ncurses (6.
