title: Clojure Portal tool: Exception viewer and other custom viewers are missing
body: <p>I can start portal and inspect values as expected. But my portal tool doesn't include viewers such as Exception viewer or class viewer as different from the <a href="https://www.youtube.com/watch?v=gByyg-m0XOg" rel="nofollow noreferrer">demo video</a>.</p>
  <p>I checked the source code of the portal and the jar distribution file. The source code contains a namespace called <code>portal.ui.viewer</code>. This namespace is missing from the portal's jar distribution. Are those viewers included into some other jar file? How can I employ those viewers?</p>
  <p>My deps.edn has the following alias</p>
  <pre><code>:inspect/portal-cli
  {:extra-deps {djblue/portal {:mvn/version &quot;0.15.1&quot;}
                              cheshire/cheshire {:mvn/version &quot;5.10.0&quot;} ; json
                              clj-commons/clj-yaml {:mvn/version &quot;0.7.0&quot;} ; yaml
                              ,}}
  </code></pre>
  <p>I start portal using:</p>
  <pre><code>clojure -M:inspect/portal-cli
  </code></pre>
  <p>My user.clj includes:</p>
  <pre><code>(ns user
      (:require [portal.api :as p]))
  (def portal (p/open))
  (p/tap)
  </code></pre>
  <p>After repl starts, I run the following commands:</p>
  <pre><code>    (tap&gt; {::exception (try (/ 1 0) (catch Exception e e))})
  </code></pre>
  <p>Here are the results:</p>
  <p><a href="https://i.stack.imgur.com/LPRGi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LPRGi.png" alt="portal 01" /></a></p>
  <p><a href="https://i.stack.imgur.com/LcKaS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LcKaS.png" alt="portal 02" /></a></p>
  <p><a href="https://i.stack.imgur.com/v9n12.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/v9n12.png" alt="portal 03" /></a></p>
  <p>According to the demo video, I am supposed to see <code>portal.viewer/ex</code> as a viewer option. Then the stack trace would be listed in the proper format as here:</p>
  <p><a href="https://i.stack.imgur.com/m3nzj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/m3nzj.png" alt="enter image description here" /></a></p>