title: Target is not a JDK root. System library was not found. Eclipse Oxygen 4.7 + Java9 error
body: <p>I'm trying to test JDK9 (jdk-9-ea+147 version) with Eclipse Oxygen IDE. </p>
  
  <p>I've installed jdk along with jre. From Eclipse Market Place I've installed Java9 Beta extension:</p>
  
  <p><a href="https://i.stack.imgur.com/7iKgx.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7iKgx.png" alt="enter image description here"></a></p>
  
  <p>The problem is, when I'm trying to add new installed jre from Eclipse I get following error:</p>
  
  <p><a href="https://i.stack.imgur.com/tqOxi.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tqOxi.png" alt="enter image description here"></a></p>
  
  <p>Interesting thing is that this error doesn't occur with installations of previous JDK versions:</p>
  
  <p><a href="https://i.stack.imgur.com/0NQ8C.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0NQ8C.png" alt="enter image description here"></a></p>
  
  <p>Does anyone encounter simillar problem with Eclipse Oxygen? Any feedback is appreciated.</p>