title: vim setting error under BufRead
body: <p>Running into a strange issue with my vimrc setting where I isolated to these 2 combination of lines if I use BufRead.</p>
  
  <p>e.g.</p>
  
  <pre><code>au BufRead *.py
      \ set softtabstop=4
      \ set shiftwidth=4
  </code></pre>
  
  <p>Now if I open a file with .py, I get error:</p>
  
  <pre><code>Error detected while processing BufRead Auto commands for "*.py":
  E518: Unknown option: set
  </code></pre>
  
  <p>This only happens under au BufRead and individually each setting works but not in combination?</p>