title: Eclipse / conditional breakpoint results in BreakpointException
body: <p>I want to debug a static inner class, which is actually a Callable. Whenever I try to set a conditional breakpoint in Eclipse I get the breakpoint error:</p>
  
  <blockquote>
    <p>The type <code>com.sun.source.tree.Tree$Kind</code> cannot be resolved. It is
    indirectly referenced from required .class files.</p>
  </blockquote>
  
  <p>What is causing this error? Is it a bug in the class/package that uses <code>com.sun.source.tree.Tree$Kind</code> but does not provide it? How do I find out which class it is? How do I resolve it?</p>
  
  <hr>
  
  <p>An example expression which should be correct is: <code>return mRtx.getNode().getNodeKey() == 74;</code></p>
  
  <p>I have changed it to <code>mRtx.getNode().getNodeKey() == 74</code> but still the same error. Recently I've found the bug and simply used:</p>
  
  <pre><code> if (mRtx.getNode().getNodeKey() == 74) {
       System.out.println("bla");
   }
  </code></pre>
  
  <p>and set a "normal" breakpoint on the "sysout" statement just in case someone has the same problem.</p>