- I tried to install `keybase`, thinking I'd get the CLI. On Linux,
casks don't work, yet I was still prompted to `brew cask install
keybase`. When I tried that (just to make sure), I got the "casks are
only supported on MacOS" error.
- This change makes it so we don't prompt people to install casks if
they're on platforms other than MacOS.
Before:
```
╭─issyl0@grus /home/linuxbrew/.linuxbrew/Homebrew ‹master›
╰─ $ brew install keybase
Error: No available formula with the name "keybase"
Found a cask named "keybase" instead.
```
After:
```
Error: No available formula with the name "keybase"
==> Searching for a previously deleted formula (in the last month)...
Warning: homebrew/core is shallow clone. To get complete history run:
git -C "$(brew --repo homebrew/core)" fetch --unshallow
Error: No previously deleted formula found.
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
==> Searching taps on GitHub...
Error: No formulae found in taps.
```
4a5b02661a