Homebrew Visual Studio error

[taslater]

Using Homebrew to install Visual Studio fails initially:

➜  ~ brew install --cask visual-studio
==> Downloading https://dl.xamarin.com/VsMac/VisualStudioForMac-8.10.21.4.dmg
==> Downloading from https://download.visualstudio.microsoft.com/download/pr/263
######################################################################## 100.0%
Error: Cask 'homebrew/cask-versions/mono-mdk-for-visual-studio' is unavailable.
Please tap it and then try again: brew tap homebrew/cask-versions

Running brew tap homebrew/cask-versions updated some Homebrew stuff. Then brew install --cask visual-studio automatically installed mono-mdk-for-visual-studio (which required my password). Visual Studio installed just fine after that.