Cannot build Apache Beam

I followed contribution-guide for Apache Beam to setup my development environment. The project compiles fine, however I always get following failure when I run mvn verify:

[ERROR] Tests run: 2, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 60.315 s <<< FAILURE! - in org.apache.beam.runners.apex.examples.WordCountTest [ERROR] testWordCountExample(org.apache.beam.runners.apex.examples.WordCountTest) Time elapsed: 32.259 s <<< FAILURE! java.lang.AssertionError: result files exist at org.junit.Assert.fail(Assert.java:88)

When I run test org.apache.beam.runners.apex.examples.WordCountTestvia IntelliJ, all assertions passes. I have a feeling there is a race condition in the assertion that is failing. Am I missing something to setup the environment?