Summarised from [here](https://apple.stackexchange.com/questions/230665/i-cant-delete-characters-in-tmux-on-macos)
1. Install ncurses (e.g. using Homebrew or Macports)
2. From that ncurses installation, generate the terminfo source file:
```bash
infocmp -x tmux-256color >tmux-256color.info
```
3. Using the **system ncurses** (`/usr/bin/tic`, not just `tic`), compile the terminfo:
```bash
/usr/bin/tic -xe tmux-256color tmux-256color.info
```
(At this point you can delete the tmux-256color.info file.)