Installing a powerline patched font will solve this. This official documentation provides description about installing poweline fonts.
There are two ways to enable powerline patched font in iTerm2.
- Set a powerline patched font as default.
- Set a powerline patched font for only Non-ASCII characters and use another font for code.
Bonus:
- Collection of powerline patched fonts
- Awesome oh-my-zsh themes
- Spaceship ZSH
- Buller Train
- powerlevel9k