title: Import is underlined with red in gradle project
body: <p>I've installed <em>Eclipse Buildship</em> (Eclipse Plugin for Gradle) and created new Gradle project in Eclipse. All works well and I can run application using gradle run configuration:</p>
  
  <p><a href="https://i.stack.imgur.com/m6tgT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/m6tgT.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/FIYqu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FIYqu.png" alt="enter image description here"></a></p>
  
  <p>but the problem is that in the code editor the dependency (imported library) is underlined with red:</p>
  
  <p><a href="https://i.stack.imgur.com/WaCqv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WaCqv.png" alt="enter image description here"></a></p>
  
  <p>The exact message that eclipse displays when hovering the red part:</p>
  
  <p><a href="https://i.stack.imgur.com/doq8X.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/doq8X.png" alt="enter image description here"></a></p>
  
  <p>How to fix it?</p>