title: Unable to run jacoco code coverage tool
body: <p>I have a maven project (<a href="https://github.com/yahoo/pulsar/" rel="nofollow noreferrer">link</a>) and I want to run code coverage on it.</p>
  
  <p>I ran the command <code>mvn test -Pcoverage jacoco:prepare-agent jacoco:report</code> on the main project pom file, but the report is not generated. Instead I get a warning saying </p>
  
  <pre><code>[INFO] --- jacoco-maven-plugin:0.7.7.201606060606:report (post-test) @ pulsar-discovery-service ---
  [INFO] Skipping JaCoCo execution due to missing execution data file.
  [INFO] 
  [INFO] --- jacoco-maven-plugin:0.7.7.201606060606:prepare-agent (default-cli) @ pulsar-discovery-service ---
  [INFO] argLine set to -javaagent:/home/jai1/.m2/repository/org/jacoco/org.jacoco.agent/0.7.7.201606060606/org.jacoco.agent-0.7.7.201606060606-runtime.jar=destfile=/home/jai1/pulsar/pulsar-discovery-service/target/jacoco.exec
  [INFO] 
  [INFO] --- jacoco-maven-plugin:0.7.7.201606060606:report (default-cli) @ pulsar-discovery-service ---
  [INFO] Skipping JaCoCo execution due to missing execution data file.
  </code></pre>
  
  <p>Can someone suggest how can I generate the code coverage report with this <a href="https://github.com/yahoo/pulsar/blob/master/pom.xml" rel="nofollow noreferrer">pom file</a>. I am using apache-maven-3.3.9 and testNG.</p>