title: How to figure out what error my Java Eclipse project has?
body: <p>I've created a Java project from existing source with an Ant build script in Eclipse. I cannot run my project because Eclipse tells me that there is at least one error in it.</p>
  <p>Now, I know that the project runs fine on the command line, so I suspect an Eclipse configuration error.</p>
  <p>As far as I can tell, the only feedback that I have from Eclipse is</p>
  <ol>
  <li><p>a little red X on my project in the Package Explorer window
  <a href="https://i.stack.imgur.com/Bddhy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Bddhy.png" alt="Eclipse Error Package Explorer" /></a><br />
  <sub>(source: <a href="http://gregmattes.com/EclipseErrorPackageExplorer.png" rel="nofollow noreferrer">gregmattes.com</a>)</sub></p>
  </li>
  <li><p>and dialog window when I try to run the project says there are errors in the project
  <a href="https://i.stack.imgur.com/NJIB5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NJIB5.png" alt="Eclipse Error Dialog" /></a><br />
  <sub>(source: <a href="http://gregmattes.com/EclipseErrorDialog.png" rel="nofollow noreferrer">gregmattes.com</a>)</sub></p>
  </li>
  </ol>
  <p>This is all wonderful, but <em><strong>what is the error?</strong></em></p>
  <p>Is there a &quot;show me the next error&quot; button somewhere?</p>
  <p>In the past, on other Eclipse projects, I've notice other little red X's on folders containing source files with errors, the little red X's appear on the source files as well. I scanned (manually) through all of the source files and I haven't found any other red X's (again, where is the &quot;next error&quot; button?).</p>
  <p>If I select the &quot;Proceed&quot; button I am greeted with a <code>java.lang.NoClassDefFoundError</code> for my main class, which makes me suspect a classpath issue. I've checked the classpath, and I'm fairly certain that it's correct. Is there a way to see the <em>exact</em> jvm command line that Eclipse is invoking? I realize that it might be invoking the JVM programmatically, and not on a &quot;real&quot; command line. In any case, is there a way, other than the run configuration dialog, to see what is <em>actually happening</em> when I hit the &quot;Proceed&quot; button?</p>