title: Why is this Web.Debug.config not working?
body: <p>I'm trying to disable custom HTTP errors in my debug builds.  I have this in <code>Web.config</code>:</p>
  
  <pre><code>&lt;configuration&gt;
    [...]
    &lt;system.webServer&gt;
      [...]
      &lt;httpErrors errorMode="Custom" existingResponse="Replace"&gt;
        &lt;remove statusCode="404" subStatusCode="-1" /&gt;
        &lt;remove statusCode="403" subStatusCode="-1" /&gt;
        &lt;remove statusCode="500" subStatusCode="-1" /&gt;
        &lt;error statusCode="403" path="/errors/403" responseMode="ExecuteURL" /&gt;
        &lt;error statusCode="404" path="/errors/404" responseMode="ExecuteURL" /&gt;
        &lt;error statusCode="500" path="/errors/500" responseMode="ExecuteURL" /&gt;
      &lt;/httpErrors&gt;
    &lt;/system.webServer&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>And this in <code>Web.Debug.config</code>:</p>
  
  <pre><code>&lt;configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform"&gt;
    [...]
    &lt;system.webServer&gt;
      [...]
      &lt;httpErrors errorMode="Detailed" xdt:Transform="Replace"&gt;&lt;/httpErrors&gt;
    &lt;/system.webServer&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>And yet on Debug builds I still get the custom error pages.  Should this transform not replace the <code>httpErrors</code> element with one that sets it back to detailed error messages?</p>