It's redirected to cleartext, though this URL will be opened
in a browser so it won't be something hidden, and maybe
Oracle will fix this in the future.

`ENV.prepend_path "PATH", which("emacs").dirname` in the emacs
requirement was causing us to end up invoking /usr/bin/clang instead
of /usr/local/Homebrew/Library/Homebrew/shims/super/clang.

This matches Linux where this behaviour was original imported from.

Neither python nor python3 are available from Caskroom.

Signed-off-by: Bob W. Hogg <rwhogg@linux.com>

In this case `HOMEBREW_VERSION` is `>1.1.0 (no git repository)` so these
tests failed. This was the cause of the Homebrew/homebrew-test-bot
Linux CI failures as it was testing a shallow clone.

Fix the error:
brew sh --cc=llvm_clang <<<'clang --version'
Failed to execute llvm_clang --version

- Check if the JSON is definitely invalid (< 2 characters)
- Output the arguments that were passed to Rubocop

Don't use the basename but instead use the Formulary logic for rack
formula resolution.

Fixes #2288.