title: xmllint returns XPath set is empty
body: <p>What I do wrong?
  I get XPath set is empty when run the following command.
  <code>xmllint --xpath './/PackageReference[@Include=&quot;Tips&quot;]/Version/text()' sdk/Test/TestSample.xml </code></p>
  <p>Please find below the xml file content.</p>
  <pre><code>&lt;Project DefaultTargets=&quot;Build&quot; ToolsVersion=&quot;4.0&quot; xmlns=&quot;http://schemas.microsoft.com/developer/msbuild/2003&quot;&gt;
  &lt;ItemGroup&gt;
   &lt;PackageReference Include=&quot;Tips&quot;&gt;
     &lt;Version&gt;2.2.2&lt;/Version&gt;
   &lt;/PackageReference&gt;
  &lt;/ItemGroup&gt;
  &lt;ItemGroup&gt;
   &lt;PackageReference Include=&quot;Hips&quot;&gt;
     &lt;Version&gt;1.1.1&lt;/Version&gt;
   &lt;/PackageReference&gt;
  &lt;/ItemGroup&gt;
  
  &lt;/Project&gt;
  </code></pre>