[hk__2]

You got downvoted because the issue is not that fastball doesn’t have Roboto on their computer; it’s the website assumption that everyone has it.

[lanewinfield]

I'd say doubly, because no Cask with this name exists.

(Looks like you have to run

  brew tap caskroom/fonts

first :) )

[hk__2]

That’s true; I didn’t try the above command :)