title: Old non-existent Julia kernel still appearing in Jupyter after upgrade to 1.8, and rebuild of IJulia package
body: <p>Upgraded Julia to 1.8. Ran &quot;build IJulia&quot; to update the package. New kernel visible in Jupyter, but so is the old one (that version of Julia is removed from system).
  <a href="https://i.stack.imgur.com/3QyE4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3QyE4.png" alt="enter image description here" /></a>
  How can I get rid of this non existent Julia kernel?</p>