title: Error compiling elasticsearch5.2.1 source code
body: <p><strong>I had some difficulty compiling the ES source code.</strong></p>
  <p>1.I got elasticsearch-5.2.1 source code from <a href="https://github.com/elastic/elasticsearch/tree/v5.2.1" rel="nofollow noreferrer">https://github.com/elastic/elasticsearch/tree/v5.2.1</a>.
  2.I extarct elasticsearch-5.2.1.zip.
  3.I use the &quot;gradle build&quot; command to build in the root directory of elasticsearch-5.2.1.
  4.My gradle version is &quot;Gradle 3.3&quot;,java version is &quot;java 1.8.0_271&quot;.my OS is ubuntu 20.04.</p>
  <p>when I run &quot;gradle build&quot; command to build in the root directory of elasticsearch-5.2.1.The result is：</p>
  <p>'''
  FAILURE: Build failed with an exception.</p>
  <ul>
  <li>What went wrong:
  Execution failed for task ':test:framework:test'.</li>
  </ul>
  <blockquote>
  <p>There were test failures: 23 suites, 132 tests, 4 failures, 3 ignored (3 assumptions) [seed: 121BC3D9A1F658B1]</p>
  </blockquote>
  <ul>
  <li>Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.</li>
  </ul>
  <p>BUILD FAILED
  '''</p>
  <p>Who can help me solve this problem? Thank you very much</p>