title: angular 9 library publish error "Trying to publish a package that has been compiled by Ivy"
body: <p>I migrated my <code>angular 8.x.x</code> project to <code>angular 9.x.x</code> and when I try to publish my library, it fails with below error</p>
  
  <blockquote>
    <p>npm ERR! @candiman/website@9.0.0 prepublishOnly: <code>node --eval "console.error('ERROR: Trying to publish a package that has been compiled by Ivy. This is not allowed.\nPlease delete and rebuild the package, without compiling with Ivy, before attempting to publish.\n')" &amp;&amp; exit 1</code></p>
  </blockquote>
  
  <p>is there anything changed in the <code>angular 9</code></p>