title: Homebrew update failure on mac
body: <p>Upon doing a <code>brew update</code>, I get the following errors:</p>
  
  <pre><code>fatal: Unable to find remote helper for 'https'
  Error: Fetching /usr/local failed!
  fatal: Unable to find remote helper for 'https'
  Error: Fetching /usr/local/Library/Taps/caskroom/homebrew-cask failed!
  Already up-to-date.
  </code></pre>