title: Error in loadNamespace(name) : there is no package called 'evaluate'
body: <p>While adding code chuncks to my .rmd file a la:</p>
  
  <pre><code>```{r} %code chunck
  
  ```
  </code></pre>
  
  <p>it can't be compiled anymore, and i get a <code>loadnamespace(name)</code> error:</p>
  
  <pre><code>Error in loadNamespace(name) : 
  there is no package called 'evaluate' calls:&lt;Anonymous&gt; ... tryCatch-&gt; Trycatchlist-&gt;trycatchoone
  </code></pre>
  
  <p>Has anyone ever experienced it? And how do I resolve it?</p>