fish: Unknown command: __tmux_prompt
~/.config/fish/functions/fish_right_prompt.fish (line 4):
  __tmux_prompt
  ^
in function 'fish_right_prompt'
in command substitution
fish: Unknown command: __print_duration
~/.config/fish/functions/fish_right_prompt.fish (line 1):
__print_duration $cmd_duration
^
in command substitution
        called on line 16 of file ~/.config/fish/functions/fish_right_prompt.fish
in function 'fish_right_prompt'
in command substitution
~/.config/fish/functions/fish_right_prompt.fish (line 16): Unknown command
  printf ' (%s)' (__print_duration $cmd_duration)
                 ^
in function 'fish_right_prompt'
in command substitution