title: Getting the API error response from CycleJS HTTPDriver
body: <p>I'm trying out CycleJS with xstream and I can't find a way to both rescue an error (e.g. 422) and get the JSON response from the HTTP driver.</p>
  
  <p>To rescue from an error, I'm using xstream's <code>replaceError</code> which seems to work like this:</p>
  
  <pre><code>sources.HTTP
    .select('hello')
    .map((response$) =&gt;
      // No response$.body or response$.error, just response$.request.
      response$.replaceError(() =&gt; xs.of(errorObject))
    ).flatten()
  </code></pre>
  
  <p>However, the API returns an error message that I would like to display to the user, and it is lost if replaced with a default object. The only property on the <code>response$</code> that's set is the actual request data.</p>
  
  <p>Versions:</p>
  
  <pre><code>"@cycle/dom": "^12.2.5"
  "@cycle/http": "^11.0.1"
  "@cycle/xstream-run": "^3.1.0"
  "xstream": "^6.4.0"
  </code></pre>
  
  <p>Any ideas are appreciated!</p>